The Lean Farm: Application of Tools and Concepts of Lean Manufacturing in Agro-Pastoral Crops

Abstract

Agriculture must find new ways to reduce costs and increase efficiency to meet the rising demand for products, avoiding waste due to potential food scarcity. Through the systematic literature review methodology, this study analyzes and synthesizes the existing literature on lean manufacturing (LM) applied in agro-pastoral production, its impact on reduction in losses and waste, and productivity increases considering production function mechanism (PFM), connecting to a sustainability model based on triple bottom line (TBL). A comprehensive search strategy was used to identify relevant studies and critically evaluate them using pre-determined inclusion and exclusion criteria. The findings provide insights into LM applied in agro-pastoral production and inform future research in the field, highlighting the potential of using LM concepts by reducing losses and waste and increasing productivity. The potential for TBL impacts from application of lean concepts in agro-pastoral production suggests a tendency for growth in this area of research. A theoretical understanding of how lean tools and techniques can be applied to improve productivity and profitability in the agricultural sector is provided, as well as practical examples and recommendations for implementing lean practices in agricultural operations, aligning sustainability and LP tools and concepts.

1. Introduction

The global demand for agricultural products is growing as the world population increases, forcing changes in agriculture and livestock processes, especially in sowing, harvesting, and animal inputs. It is possible to perceive this because there is an estimate that the world population will reach 11.2 billion people at the end of this century [1], and growth in per capita consumption, which was 2200 Kcal/day in the 1960s, reached 2800 Kcal/day in the year 2009 [2]. Population and income growth will continue to increase food demand and change people’s dietary preferences [3] as drivers of transformation, mastering technological changes, including biotechnologies, digitalization, and “systemic” innovative approaches and their potential addressing drawbacks, to sustainably improve food and agricultural productivity [4]. Due to this increase in worldwide demand for agricultural and agro-industrial products, agriculture has changed the acquisition, planning, planting, maintenance, harvesting, transportation, and distribution stages [5].

Currently, the focus is on increasing large-scale productivity, inspired by manufacturing techniques and methods already used by purely industrial companies. The growth in this need takes scientific research to an important place in international institutions given its relevance and urgency [6]. The degree of change needed to ensure resilient and robust food systems operating within planetary boundaries for biodiversity requires moving beyond incremental adjustments [7].

Historically, agriculture has always had problems with operational costs and prices, becoming a relevant addressed factor because of the focal reality and variability in price and income, with economic problems standing out: the general problem of income and agricultural uncertainty [8]. In the literature reviewed, operational and inventory costs are the most mentioned, followed by logistics, transportation, and distribution costs [9]. In the 1950s, in the USA, Cochrane [10] proposed no gold average for agriculture between price and income variations. As a solution, he suggested two proposals: the first was continuation of the agricultural program in the USA, which bears the costs of price and income support in agriculture; the second was development of a production and control market system. Several years later, variations in agricultural income still have positive or negative impacts, which increase or decrease household income [11].

However, the solutions continue with initial applications, including crop rotation, selection, location of places to plant, cultivation of a combination of fruits and vegetables, and using industrial products in the agricultural process [12]. Such studies were necessary for planning use of water, soil, sowing, demand for products and crop life cycles, and maturation, among other purposes, because these factors are essential for developing models to describe agricultural behavior and planning of strategic, tactical, and operational guidelines [13,14,15]. From a life cycle perspective, agricultural production is the phase with the highest environmental costs in the agri-food sector [16].

Industrial concepts and methodologies can be used to improve these agro-pastoral processes by focusing on reducing losses and waste and supporting the literature. In recent years, several industries and sectors have adapted to lean production (LP) or lean manufacturing (LM) to become more efficient, for example, in the service sector [17,18,19], administrative processes [20], healthcare [21], and public administration [22,23]. Adapting manufacturing systems to new principles and technologies is an important measure of staying competitive and striving for the future [24]. It is a challenge for the entire organization, not just on the production floor. The same logic has been applied to farms, aiming at large-scale production, standardization, and operational management [15,25].

Losses and waste generate demand for additional work, impacting the farm’s need to increase production capacity and costs [26]. The handling, storing, processing, and distributing stages are impacted by losses and waste of 33% of the amount of food during agricultural production [13]. Food losses and waste occur at all stages of the product production chain, such as growing/breeding–processing–storage–selling–consumption [27].

The minimization and waste in production systems have many applications in manufacturing what management called lean and its philosophy to provide solutions to problems companies [28]. For instance, elimination enhances value in the manufacturing system by identifying waste to target better and more efficient approaches [29]. Lean manufacturing (LM) has become one of the essential tools used in manufacturing companies and other sectors and aims to reduce losses and waste in production processes and increase productivity. To better understand the purpose of this article, it is important to consider the four phenomena of production system components: processing (manufacturing), inspection, transport, and delay [30], conceptualized as processes and operations in a different approach of the concept known in the West, observing production in time and space. This approach also served as the basis of the theory of production function mechanism (PFM) [31,32,33].

Therefore, reduction in losses and waste can also be evaluated in two ways: by process function (PF)—related to process flow, dealing with transformation of raw materials into products—and operation function (OF)—regarding labor, with actions that perform these transformations [34,35].

Another relevant factor is the impact of reducing losses and waste in agricultural production for sustainability considering the triple bottom line (TBL) model and the relationship of social, economic, and environmental aspects for sustainable development of any business [36]. Research relating to TBL and agricultural production is identified, such as in rice production [37], agricultural industries, and supply chains [38,39].

Given the growth in the world population that needs to be fed, the importance of productivity in agriculture and livestock is clear. Therefore, it is important to apply the concepts of this philosophy to obtain results, leading us to a lean farm concept. From the combination of agricultural production needs and waste minimization, combined with the concepts of LM from a TBL viewpoint, there are three research questions:

(i) What is lean manufacturing (LM) application in agro-pastoral production?

(ii) What are the impacts of a reduction in losses and waste and an increase in productivity relating to the process function (PF) and operation function (OF) of lean manufacturing (LM)?

(iii) What is the relationship between applying LM concepts and impacts on TBL pillars?

The objective of this article is to identify which tools related to lean manufacturing (LM) are applied in agro-pastoral production, their impacts on reduction in losses and waste and productivity increases considering the view of process function (PF) and operation function (OF), and, finally, relate them to a sustainability model based on TBL.

This research problem has its basis in the notions that LM concepts support reduction in losses and waste and increased productivity in this type of production system, for example, healthcare service [40], manufacturing, and construction [41]. The same relationship between waste and loss reduction can be applied to any production system, including agricultural production. Reduction in waste and losses in agricultural production positively impacts the TBL pillars of sustainability [36]. The framework presented in Figure 1 provides the interpretation that lean manufacturing (LM)—through its concepts, models, and tools—positively impacts operational results, farm productivity, waste reduction, and sustainability.

According to Figure 1, implementing LM concepts and tools in agro-pastoral production can lead to more efficient use of resources, such as land, water, and energy, which can contribute to the environmental sustainability of the production process. Additionally, a reduction in waste and losses can also lead to a reduction in use of chemicals and other inputs, which can positively impact the social sustainability of the production process. Furthermore, applying LM concepts and tools can also increase the quality of the products produced, which can positively impact the economic sustainability of the production process. This can lead to increased customer satisfaction and higher profits for the agro-producer.

Overall, implementing LM concepts and tools in agro-pastoral production can provide a holistic approach to sustainability that addresses the TBL framework’s economic, social, and environmental pillars. This can lead to a more sustainable and profitable agro-pastoral production process, benefiting both the producer and the environment.

This research is justified because it relates lean manufacturing (LM), which is one of the most applied topics for reducing losses and waste and increasing productivity in production systems, to the prospect of agro-pastoral production due to the growing global demand for food that impacts TBL factors.

2. Materials and Methods

2.1. Lean Manufacturing (LM) Concepts and Lean Farm

New ideas and models do not come out of nowhere, and people need to be motivated. This was the case with lean manufacturing (LM) using the base concepts of the start of our history in Japan after many difficulties after the Second World War, in which they sought new models and concepts to improve processes and increase productivity [28,42]. For Ohno [42], the lean production system’s primary basis was eliminating waste, reducing costs, and increasing competitiveness. He understood that all waste had raised costs and time, and its causes needed to be eliminated.

Lean thinking starts from the value created for the end customer by the producer [28]. For this action to be successful, it is necessary to define what to deliver to the customer to understand their needs and obtain their satisfaction. The perception of value can be acquired through the relationship between performance and product cost. It is necessary to understand the environment in which it is inserted and add value to that environment [43]. Over the last 30 years since Womack, Jones, and Ross’s publication, lean principles have been up to date. They can support implementing more efficient, effective, and economically sustainable manufacturing operations in a real industrial environment [44].

There are five principles of lean production (LP) [28]:

• Accurately separate customer value;
• Identify the value stream for each product;
• Promote the value flowing without interruptions;
• Let the customer extract value from the producer;
• Pursuing perfection.

By readapting these concepts and applying them to agro-pastoral production, we can cite them as:

• Listen to customers and understand their real needs;
• Create a value map for each product from the purchase of inputs until the final payment;
• Seek development flowing without interruption;
• Produce only the quantity that can be sold and does not produce beyond demand;
• Keep developing a culture of continuous improvement on farms/organizations.

Lean manufacturing (LM) has identified seven main types of waste and losses that need to be eliminated [35,43]:

• Overproduction: producing too much or too soon, resulting in a poor flow of parts and information or an excess of inventory;
• Waiting: long periods of idleness of people, parts, and information, resulting in poor flow, as well as long lead times;
• Transportation: excessive movement of people, information, or parts, resulting in unnecessary expenditure of capital, time, and energy;
• Overprocessing: use of the wrong set of tools, systems, or procedures, usually when a simpler approach can be more effective;
• Inventory: excessive storage and lack of information or products, resulting in high costs and poor performance of customer service;
• Movement: disorganization of the work environment, resulting in poor performance of ergonomic aspects and loss of items;
• Defective products: frequent problems with process charts, product quality problems, or poor delivery performance.

Antunes Junior et al. [34] point out the production function mechanism (PFM), based on concepts presented by Shingo [31,32,33] on wastes from the production systems, in which all activities can be segregated by process and operation. Process function (PF) is perceived in materials or products at different production stages and in processing, inspection, transportation, and storage. The losses related to this function are overproduction, transportation, overprocessing, inventory, and defective products. The losses linked to the operation function (OP) arise at different stages and are related to machines and operators that perform value aggregation. Waiting and motion are related to this function. For the authors, the conceptual rupture made possible by the PFM and characteristic of the construction is associated with recognizing that the non-theoretical process is the sum of the operations. In other words, the basic nature of the PF and its precedence over the OF enables construction of a strong conceptual framework for production systems design.

Introduced in the early 1990s, John Elkington coined in 1994 the triple bottom line (TBL) concept, which is the triple principles of sustainability involving the relationship between people, planet, and profit as a basis for decision-making in sustainable business. Sustainability must be considered in the environmental aspect of caring for the planet and natural resources; the social aspect of caring for people and social groups; and the economic aspect of caring for the perpetuity of the business, market, and industries. Seeking sustainability in the TBL concept, with social, environmental, and economic components, is a way to foster development of innovations in organizations and to obtain better competitive performance [45].

To effectively implement lean practices, a thorough understanding is necessary, as well as a shift in organizational culture and employee mindset. By incorporating lean activities, small- and medium-sized businesses can see and measure the benefits of these practices. Support from government agencies, educational institutions, and professional organizations can assist these companies in overcoming any obstacles that may arise during the transition process [46].

Difficulties after COVID-19 also offer risks to achieving resilience and business sustainability [47] since the connection between business sustainability and knowledge risks must be established [48], especially with attention to sustainable operations by increasing awareness about the growing population, which, at a global level, cannot be mastered with limited resources [49].

Implementing lean production (LP) concepts impacts reduction in losses and waste, generating greater productivity. The relationship between application of LP concepts positively influences sustainability of agricultural production systems, meeting demand (people), production with lower cost (economic), and using fewer material resources and space (planet), reflecting positive sustainability impacts [49].

2.2. Conducting Research

The methodology applied in this research was a systematic literature review, which is fundamental for execution of scientific research and has its main objectives to organize the literature and develop theories based on the results found [50,51]. With such methodological aims, based on analysis of primary studies, to find, evaluate, and consolidate concepts that help to answer a research question or to identify research gaps in the literature, we decided to use the proposed model [50], whose steps are detailed in Figure 2.

The applied model consists of seven stages. The description of step 1 can be found in the Introduction; steps 2, 3, 4, and 5 are in this section, and steps 6 and 7 are in Results.

The review ensures that the three research questions are answered and met by linking each step of the systematic literature review, as detailed in Figure 2, to the study objectives. This approach provides a comprehensive and robust review that can be used to support the findings and conclusions.

Step 1: Defining the question and conceptual framework: 3 research questions were stated for this systematic literature review: “What is lean manufacturing (LM) application in agro-pastoral production? What are the impacts of the reduction of losses and waste and the increase in productivity relating to the process function (PF) and the operation function (OF) of lean manufacturing (LM)? What is the relationship between applying LM concepts and impacts on TBL pillars?” The study objectives are to identify the tools related to LM that are applied in agro-pastoral production, evaluate their impacts on reduction in losses and waste and productivity increases, and relate them to a sustainability model based on TBL. Development of the conceptual framework relates to application of LP tools, their application in agricultural production systems, and the relationship between the TBL pillars for sustainability perspective.

Step 2: Definition of working team: In choosing the staff, two groups were formed, with 2 PhDs responsible for defining the search criteria for inclusion and exclusion and evaluating the quality of publications.

Step 3: Search strategy: In defining the search strategy stage, it was necessary to define what to look for, where to look, minimize bias, which studies to consider, and what the search length is [50]. The searches were performed with keywords, titles, and summaries in the Scopus Elsevier database. The base’s definition was due to its indexing with the largest number of journals with higher impact and relevance factors available on the Capes periodical portal. The searched terms were “lean”; “lean manufacturing”; “farm”; “agriculture”; “agro-pastoral”. These terms were combined as (“lean” OR “lean farm” OR “lean manufacturing”) AND (“farm” OR “agriculture” OR “agro-pastoral”) from the year 2000 to find relevant studies that address the research question and study objectives. Data collection has covered the period from 2000 to now since, at that time, investigations on the topic have increased.

Step 4: Search, eligibility, and coding: To the results of these searches, we applied the inclusion and exclusion criteria; exclusion of studies occurred based on the following:

• Exclude articles that do not have at least one of the following terms in their title: lean, lean manufacturing (LM), improvements, reduction, cost, productivity, farm, agriculture, waste, production, increase, value, chain, supply chain, operational, improve, management, farming;
• After reading the summary, discard articles that do not approach empirical applications of tools and methodologies proposed by lean manufacturing (LM) to improve production processes related to agriculture;
• After reading the texts in full, exclude articles that do not address the impacts of applying lean manufacturing (LM) in agriculture processes.

Step 5: Quality assessments: In qualitative evaluation of publications, an ecological triangulation approach was used to generate synthesis of results [52]. In this evaluation, based on the literature, we attempt to understand which strategies were used with lean tools, applications, characteristics, results, and the relationship with the pillars proposed by TBL. This approach provided a comprehensive understanding of use of lean tools and their relationship with TBL, highlighting the potential for these tools to contribute to sustainable development.

Step 6: Summary of results: The studies found and evaluated for quality in the previous steps were synthesized to identify common themes and patterns related to the tools used in LM, their impacts on reduction in losses and waste, and productivity increases, and their relationship to a sustainability model based on TBL.

Step 7: Results presentations: The systematic literature review provided a conclusion that summarizes the findings through Tables 1–7, presented in the Results section, and provides recommendations for future research in the area of LM, agro-pastoral production, and sustainability. The conclusion also links the findings back to the research question and study objectives, highlighting how they have been addressed through the literature review process.

3. Results

The quantitative results of the applied criteria for inclusion and exclusion shown in Materials and Methods are available in Figure 3.

After this stage, seventeen articles remained for full reading and evaluation to generate a discussion of the results. The high number of excluded articles resulted because many publications apply the term “lean” to lean meat, such as lean or low-fat meat. Information about the evaluated papers is described in

Table 1. Overview of full papers selected for qualitative analysis.

Paper’s Title	Author/Year	Main Subject 1
Feasibility model study for Blumbangreksa product model based on lean startup meth	[53]	Increases in shrimp productivity
Lean in Swedish agriculture: strategic and operational perspectives	[54]	Testing a lean structure in the agricultural sector
Lean management in the rice industry; case study at Widasari, Indramayu district	[55]	Process flow in the rice industry
A Green Lean approach to global competition and climate change in the agricultural sector: a Swedish case study	[56]	Lean deployment structure on farms
Lean Production System: evaluation in a Laying Poultry Farm	[57]	Lean case study on a chicken farm
The Improvement of logistic management using Lean and RFID technology	[58]	Reducing times of logistic operations on rice production
Value stream mapping for sustainable change at a Swedish dairy farm	[59]	VSM on a dairy farm
Towards the integration of lean principles and optimization for agricultural production systems: a conceptual review proposition	[60]	Organization of decision-making models in agriculture
Decreasing the Environmental Impact in an Egg-Producing Farm through the Application of LCA and Lean Tools	[61]	Reducing environmental impact on chicken and egg farm
Implementation of Lean Manufacturing Principles in a Vertical Farming System to Reduce Dependency on Human Labor	[62]	Vegetable growing layout
Lean Six Sigma Analyst in Packing House Lembang Agriculture Incubation Center (LAIC)	[63]	Reduction in activities that do not add value to the vegetable packaging process
Lean principles in vertical farming: A case study	[64]	Production increments with vertical farming
Organizational innovation in the context of family farms: Lean diagnosis	[65]	Lean concepts in production in lettuce family farming
On Heijunka manufacturing system for agricultural products: Application of learned production management model for agri-businesses	[66]	Application of Heijunka for productivity and profit increments
Application of Value Stream Mapping for Lean Operation: An Indian Case Study of a Dairy Firm	[67]	Application of VSM to identify non-value-adding activities in the dairy production system
Operational model for minimizing costs in agricultural production systems	[5]	Applying operations research modeling for cost reduction and decision-making in banana production.
Toward sustainable primary production through the application of lean management in South African fruit horticulture	[15]	Evaluation of 132 fruit horticulture farms on lean implementation practices to reduce process losses

¹ Main subject from the qualitative analysis.

.

Through the results of Table 1, it is possible to understand implementation of lean principles and techniques in the agricultural sector leading to significant increases in productivity and profitability. Evaluating the data, two types of research can be seen. The first one is regarding applications of concepts from lean manufacturing (LM) for specific crops, generating some specificity in the presented results, such as rice cultivation [55] and shrimp farming [53], among others. The second one is generic cases where the model concepts can be applied more broadly, such as VSM applied in farms [59] and application of Heijunka [66], among others. The table shows the results of various case studies and evaluations of lean implementation practices in the agricultural sector, including use of lean tools, such as VSM, Heijunka, and operations research modeling, connected to the first research question: what is lean manufacturing (LM) application in agro-pastoral production?

Table 2. The number of publications by country.

Country	Number of Publications 1	Author/Year of Publication
Indonesia	3	[53,55,63]
Sweden	3	[54,56,59]
Colombia	2	[5,60]
Brazil	1	[57]
Thailand	1	[58]
Mexico	1	[61]
Malaysia	1	[62]
Japan	1	[66]
Portugal	1	[65]
United Kingdom	1	[64]
India	1	[67]
South Africa	1	[15]

¹ Research predominance from the qualitative analysis.

shows the number of publications by country.

Evaluating the results presented in Table 2, there is a predominance of research in these areas in Indonesia and Sweden, with three publications in each country and a mix with one publication in different countries. In Sweden, a couple of authors are references on the subject and their research can be considered to emphasize information on lean farms. Still connected to the first research questions, these countries may have a strong interest in implementing lean principles and techniques in their agricultural operations. Additionally, a mix of one publication in different countries suggests a growing interest in implementing lean practices in the agricultural sector globally. After fully reading these articles,

Table 3. List of lean tools applied in agro-pastoral activities.

Author/Year	Tool Applied 1
[53]	Eight dimensions of quality (performance, features, compliance, reliability, ease of maintenance, durability, aesthetics, and perceived quality)|Lean Canvas—to evaluate customer value proposition|Business feasibility study.
[54]	Value stream mapping (VSM)|Problem-solving methods (PDCA and A3)|SMED|5S|Standardized operation procedure.
[55]	Value stream mapping (VSM)|6S (traditional 5S added for security).
[56]	5S|Standardized operation procedure|Visual management.
[57]	In farm poultry, a case study was applied to evaluate the 14 lean principles proposed by Liker [68]: Philosophy|Process|Employees, and partners|Problem-solving.
[58]	Value stream mapping (VSM)|RFID applied in logistical processes.
[59]	Value stream mapping (VSM).
[60]	Taxonomic modeling techniques and operational research in agriculture through a systematic literature review.
[61]	Life cycle assessment (LCA)|Value stream mapping (VSM).
[62]	Layout organization|Karakuri Kaizen.
[63]	Value stream mapping (VSM)|Flow chart.
[66]	Heijunka.
[28,35]	Value stream mapping (VSM)|SMED|Flow chart.
[64]	Value stream mapping (VSM).
[67]	Value stream mapping (VSM).
[5]	Applying mathematical modeling through lean principles.
[15]	Supplier Feedback|Developed Suppliers|Involved Customers|Pull|Flow|Setup Time Reduction|Statistical Process Control|Total Preventative Maintenance|Involved Employees|Signaling (Kanban).

¹ Lean tool used on the seventeen articles fully analyzed.

was prepared to identify the tools applied.

Evaluating the data presented in Table 3, it is possible to observe application of several tools from LM.

Table 4. Summary of LM tools applied in agro-pastoral productions.

Tools Applied	Number of Applications	Impacts Improvement: Process Function (PF) or Operation Function (OF) 1
Value stream mapping (VSM)	9	Process Function (PF)
Flow chart	3	Process Function (PF)
5S	2	Operation Function (OF)
Standardized operation procedure	2	Operation Function (OF)
SMED	2	Operation Function (OF)
Employees and partners	2	Process Function (PF)
5S	2	Operation Function (OF)
Standardized operation procedure	2	Operation Function (OF)
Eight dimensions of quality	1	Process Function (PF)
Lean Canvas	1	Process Function (PF)
Business feasibility study	1	Process Function (PF)
Problem-solving methods	1	Process Function (PF)
6S (traditional 5S added for security)	1	Operation Function (OF)
Visual management	1	Operation Function (OF)
Philosophy	1	Process Function (PF)
Process	1	Process Function (PF)
Problem-solving	1	Process Function (PF)
RFID applied in logistical processes	1	Process Function (PF)
Life cycle assessment (LCA)	1	Process Function (PF)
Layout organization	1	Process Function (PF)
Karakuri Kaizen	1	Process Function (PF)
Heijunka	1	Process Function (PF)
Math modeling	1	Process Function (PF)
TPM	1	Process Function (PF)
KANBAN	1	Process Function (PF)
Statistical Process Control	1	Process Function (PF)
Developed Suppliers	1	Process Function (PF)
Eight dimensions of quality	1	Process Function (PF)

¹ Relationship with elimination of PF and OF losses.

presents a summary of the tools applied in lean farms, the amount that appear in the evaluated papers, and the impact of their application considering elimination of process function (PF) and operation function (OF) losses.

Evaluating the data presented in Table 4, application of lean (concepts and tools) can be viewed in twenty different ways, demonstrating how lean can adapt farms’ production in several ways. Among the tools applied, value stream mapping (VSM) with nine applications stands out after the Standardized Operation Procedure and Flow Chart, with two applications each.

The great index of application of the VSM can be understood as the beginning of application of lean in farms since, in general, the tool generates information to interpret the productive system and opportunities for improvement. It supports analysis of value-adding and non-value-adding activities, waiting times, and opportunities to reduce losses and waste. The other applications are related to the solution needed for each problem evaluated and its characteristics.

Table 5. Main results of application of lean concepts.

Author/Year	Main Results 1
[53]	The product had key metrics achieved, for example, the survival rate of at least 90% in shrimp farms with intensive systems, a shrimp seedling survival rate of at least 75% for shrimp farms in the traditional system, and an increase of 37% in sales for the year.
[56]	Of 34 evaluated farms, 9 are in the pre-implementation phase, 11 are implementing, and 14 have already been implemented 100%. The results are loss reduction in processes in all the evaluated farms.
[55]	The waiting time in the post-harvest process gradually decreased from 68.41 h to 65.65 h. In addition, the estimated efficiency is about 99.87% of the total delivery time, adding the production value, and only 0.13% of the wasted time is in the loading process.
[54]	Evaluation of 34 farms to identify which areas have implemented improvements based on lean manufacturing (LM), examples of the improvements, and the number of positive effects.
[57]	The process pillar had better results, with 95% adherence. The pillar of employees and partners had the worst adherence, with 73%. Overall, the farm has 84% adherence to the model proposed by Liker [68].
[58]	Compared to the total time in the current operation, the future of the operation (lean and RFID) can result in a time reduction from 3.73 to 3.11 min. Further, according to the analysis of the interruption event’s point, this operation can yield three years, with a return on investment of 28.77%.
[59]	After three years of actions to improve the process [54,56], improvements were achieved in seven indicators: Milk yield (kg of energy corrected per cow/year): from 9600 to 11,000. Age of first delivery (months): 26 to 24. Milk quality (somatic cell count, cells/mL of milk): from 275,000 to 150,000. Calf mortality (%): from 6 to 2. Fat (%): from 4.4 to 3.9. Milk protein (%): from 3.4 to 3.3. The growth rate of calves (kg of body weight at weaning): from 70 to 90.
[60]	Evaluates application of lean in agriculture and taxonomic modeling techniques.
[61]	With the eco-efficient scheme and the equipment’s adjustment in the consumption/energy ratio, a reduction of 49.5% in the total energy consumption of the farm was obtained without compromising the current production process. There was also an average savings of 56.3% in environmental impacts on egg production’s electrical cost.
[62]	Experimental results show that 90% of the 36 cabbage seedlings grew successfully within six weeks.
[63]	Application of VSM to reduce activities that add and do not add value. In activities that add value, time was reduced by 2.4%, and, in activities that do not add value, the reduction was 64.74%.
[66]	Develops a Heijunka model for leveling production to standardize productivity and impact customer satisfaction.
[65]	Application of VSM to reduce losses and propose a new process flow. Reduction of 23.2% of the time in activities that do not add value.
[64]	VSM to assess non-value-adding activities.
[67]	Application of VSM to separate non-value-added but necessary and value-added activities. The total lead time was reduced by 34.79% in milk products.
[5]	Applying mathematical modeling that reduced the production cost by approximately 59% to solve the planning of agricultural production systems in the stages of sowing, tillage maintenance, and banana harvest.
[15]	The implementation index of the ten lean dimensions proposed [69] was evaluated in 132 fruit farming operations in South Africa. A higher practice of lean concepts was found on 44 farms.

¹ Main results of lean tools applied in agro-pastoral productions.

presents the main results of application of lean tools.

The study objectives are to identify the tools related to LM that are applied in agro-pastoral production, evaluate their impacts on reduction in losses and waste and productivity increases, and relate them to a sustainability model based on TBL. Thus far, the studies and evaluations presented in Table 5 demonstrate the effectiveness of implementing lean principles and techniques in the agricultural sector. Overall, the results demonstrate that implementing lean principles and techniques can lead to significant improvements in the agricultural sector, with reduced costs, increased efficiency, and improved productivity and profitability.

Each tool is popularly used in lean farms for different reasons:

• Value stream mapping (VSM) is used because it helps identify and eliminate non-value-adding activities, which results in a reduction in losses and waste and an increase in productivity.
• Heijunka is used because it helps level production to standardize productivity and impact customer satisfaction.
• Statistical process control and PDCA are used because they help identify and eliminate defects and improve product quality.
• A3 and visual management are used because they help identify and solve problems and improve the flow of the process.
• 5S and SMED are used because they help organize the work environment and reduce time required to change over equipment.
• RFID is used because it helps track and monitor inventory and improve the flow of the process.
• 6S enhances the 5S elements and includes safety in the process.
• Kanban is used to signal the need for replenishment and improve the flow of the process.
• In addition, mathematical modeling, eco-efficient schemes, and taxonomic modeling techniques are used to solve planning of agricultural production systems, reduce production costs and environmental impact, and improve the growth rate of seedlings.

Kravenkit and Arch-Int [58] presented in their research one evaluation of processes, losses, and value-added time during processing in the rice industry. In the study, eight processes were evaluated (purchases and orders, receipt, storage of rice, production, packaging, storage of the finished product, order separation, and transport). The process had a value-added time of 3731.5 min (with a waiting time of 1 day, 6 h, and 30 min), with 19 employees working. The objective was to reduce value-added activities without focusing on reducing waiting times. After process improvements, the value-added time increased to 3114.5 min, with 17 operators working. After improvements, the value-added time was reduced by 16.5% and 17.6% in the total number of workers.

Satolo et al. [57] presented a case study of an egg-producing company, which seeks to understand the degree of adherence to lean manufacturing (LM) concepts in the processes based on the model proposed by Liker [68]. One among fourteen principles is related to philosophy, seven to processes, three to employers and partners, and three to problem-solving. They rated each principle by giving it a score from 1 to 5, as Figure 4, adapted by Satolo et al. [57], shows.

We realized that the philosophical principle had an adherence of 80%; processes, 94.3%; employers and partners, 66.6%; and problem-solving, 86.6%, highlighting the importance of working on leadership development projects and integration with suppliers.

In the research performed by Pakpahan et al. [53], five lean startup concepts, eight dimensions of quality, an empathy map, an experiment framework, and a lean canvas are combined to increase the productivity of shrimp farming, which, in Indonesia, is considerably lower than other countries. The research showed that water quality is fundamental for the productivity of the shrimp, in which there was an increase in the survival of these crustaceans, and sales improved by 37% after technical application.

A paper written by Melin and Barth [54] describes a case study composed of a sample of 34 farms that participated in a lean farm program, in which they were separated into three phases: pre-implementation, implementation practices, and post-implementation. Each case received its classification according to the number of improvements implemented. Post-implementation farms used tools such as VSM for problem-solving; farms with implementation practices used SMED, maintenance techniques, improvement systems, and technical consulting support; finally, pre-implementation farms applied necessary tools 5S and standardization in isolated areas on farms.

In another study, Barth and Melin [56] describe a framework with steps for implementing lean manufacturing (LM). Using the same sample as in the previous paper, the effects of certain factors of the lean tool application were investigated, and 72% of the answers appointed positive effects after implementing lean methodologies.

Perdana et al. [55] discuss the rice processing industry in Indonesia. They applied value flow mapping, evaluated the periods of value addition, and waited between processes to execute the proposed future map. Consequently, they reduced the total lead time by 4% through process improvements, from 68.41 h to 65.65 h of the total lead time.

In the study by Caicedo Solano et al. [60], there is a literature review on lean principles applied to agriculture. The magazine’s quality was compared to the number of publications on agriculture and how much they approached lean and taxonomic modeling techniques and operational research in agriculture until that moment.

Estrada-González et al. [61] conducted a study in the egg production industry in Mexico, wherein they apply the concepts of the Life Cycle Assessment (LCA) and value stream mapping (VSM) to reduce environmental impacts and consumption of energy through the use and reuse of waste from the production process.

Melin and Barth [59] describe the evolution of productivity indicators on a dairy farm in Sweden three years after implementing the concepts of LM and VSM. Many indicators have undergone performance improvements. It is noteworthy that milk production has increased by 15%, and the cows’ health has improved significantly, which could be measured by the number of cells in the milk, with the weight of the calves at weaning increasing by 28%.

Heng et al. [62] checked the concept of lean manufacturing (LM) to create a vertical vegetable production system in closed environments. They work in layout organization, lighting, and irrigation. In addition to the good results obtained, the product can be grown in urban centers, bringing it closer to the consumption points.

De Oliveira et al. [64] performed VSM and managed to reduce non-value-adding activities by 31% by restructuring activities and eliminating unnecessary activities. Moreover, the layout of the vertical farm was changed, reducing part of the unnecessary movement of materials and people.

Ariffien et al. [63] applied the VMS to reduce activities that add and do not add value. In activities that add value, time was reduced by 2.4%, and, in activities that do not add value, the reduction was 64.74%.

Katayama and Aoki [66] proposed a Heijunka model to level production considering the relation of supply, demand, inventory, lead time, and safety stock. The proposed model is validated through experiments, increasing productivity, and reaching demand more precisely.

Aguiar et al. [65] mapped the value stream in two family lettuce farms, proposing new process flows that focus on reducing losses and prioritizing activities that add value to the process. It was possible to reduce the number of workers and total production time and eliminate unnecessary operations.

Kumar and Shankar [67] applied the VSM tool to produce dairy foods. In the application, the activities are segregated into three types: those that add value, those that do not add value and are necessary, and those that do not add value. The activities involved Pasteurizer Tank, Separator Tank, Filling Tank, and Time Associated with the Waiting Time Activity in Cold Room. Reduction in the total lead time from 46 h to 30 h occurred, in which 13 add value and 17 do not add value but are essential activities, generating a reduction of 34.79% in total lead time.

Caicedo Solano et al. [5] performed mathematical modeling, intending to maximize use of resources. The objective function minimizes associated costs and constraints, integrating activities that contain lean manufacturing principles (use of natural resources, labor, machinery, product quality, waste reduction in processing times, waiting, and crop yields). The model offers a cost reduction of nearly 59% of the costs related to production waste.

Pearce et al. [15] presented a study with 132 fruit farming operations in South Africa, analyzing the level of implementation of lean practices. It was statistically segregated that 44 farms (33.33%) have a high level of implementation. Farms with a high level of implementation are more sustainable, and larger farms have a higher level of implementation of lean practices and are more sustainable.

In a general way, clearly, among the publications analyzed, application of lean philosophy improves the results by applying a set of tools and adapting them to the model that best brings results to the evaluated systems.

From evaluation of the seventeen selected papers, it was possible to see the application of many tools from lean production (LP) for agro-pastoral production. All the evaluated publications presented positive results in the evaluated indicators supported by applying the tools. The five LP tools most applied were VSM [54,55,58,59,61,63,64,65,67], 5S [54,56], Standardized Operation Procedure (SOP) [54,56], Flow Chart [15,63,65], SMED [54,65].

Considering seven losses of the productive systems (overproduction, waiting, transport, overprocessing, inventory, movement, and defect) [42], it is possible to perceive that all of them were fought in the evaluated papers, relating to activities of process function (PF) and operation function (OF), wherein the first PF has the characteristics of manufacturing or processing, inspection, transport, storage or waiting. The second OF relates to activities between men and machines. The list of losses and wastes combated is detailed in

Table 6. Relationship between the losses and wastes attacked and the tools applied.

Losses and Waste 1	Applied Tool	PF or OF	Applications in the Evaluated Studies
Overproduction	VSM|Heijunka, Pull	PF	[15,54,55,58,59,61,63,64,65,66,67]
Waiting	SOP|Visual management	OF	[54,56]
Transportation	Layout organization|Flow Chart	PF	[15,62,63,65]
Overprocessing	Flow Chart	PF	[15,63,65]
Inventory	VSM|Signaling (Kanban)|Heijunka|Pull	PF	[15,54,55,58,59,61,63,64,65,66,67]
Movement	5S|SMED|6S|RFID	OF	[15,54,55,56,58]
Defect	Statistical Process Control|PDCA|A3|Visual management|Dimensions of quality	PF	[15,53,54,56]

¹ Seven main types of losses and wastes from lean.

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Table 6 presents the relationship between losses and wastes reduced through implementation of tools proposed by lean production (LP), relating them to process function (PF) and operation function (OF). The impacts of applying lean manufacturing to agro-pastoral production can be seen in elimination of the following seven main types of waste and losses:

• Overproduction: Using tools such as VSM and Heijunka, Pull, agro-pastoral production can reduce the waste caused by overproduction by only producing what is needed when needed.
• Waiting: SOP and visual management tools can help eliminate waiting times by streamlining processes and making them more efficient.
• Transportation: Using tools such as Layout Organization and Flow Chart, agro-pastoral production can reduce waste caused by unnecessary transportation by optimizing movement of materials.
• Overprocessing: By using tools such as Flow Chart, agro-pastoral production can reduce the waste caused by overprocessing by identifying and eliminating unnecessary steps in the production process.
• Inventory: Using tools such as VSM, Signaling (Kanban), Heijunka, and Pull, agro-pastoral production can reduce the waste caused by excess inventory by only keeping what is needed when it is needed.
• Movement: Using tools such as 5S, SMED, 6S, and RFID, agro-pastoral production can reduce the waste caused by unnecessary movement by optimizing the movement of materials and people.
• Defect: Using tools such as Statistical Process Control, PDCA, A3, Visual Management, and Dimensions of Quality, agro-pastoral production can reduce the waste caused by defects by identifying and eliminating the root causes of defects.

Through the presented results, five publications reduce losses in OF [15,54,55,56,58] and fourteen in PF [15,53,54,55,56,58,59,61,62,63,64,65,66,67] through application of LP tools. It is possible to verify that a great part of the applications of LP concepts in agro-pastoral productions is related to process function (PF), wherein better flow of process and material flows for gains in efficiency and productivity are required [34,42].

According to the presented results, the researchers have found that various tools derived from lean manufacturing have been applied in agro-pastoral production to address specific areas of losses and waste, such as overproduction, waiting, transportation, overprocessing, inventory, movement, and defects. These tools have effectively reduced losses and waste, increasing productivity and efficiency in agro-pastoral production. Application of these tools can have positive economic, social, and environmental impacts. The process is still at an early stage, with many future opportunities for applying lean concepts in agro-pastoral production. The researchers have discovered that implementing lean manufacturing concepts and tools can positively impact productivity and profitability in the agricultural sector while also being aligned with sustainability.

Examples of productivity results generated by applying tools related to operation function (OF): 99.87% efficiency in rice processing and loading [55], 16.52% reduction in total process lead time [58], and better productivity rates through implementation of LP practices [15,54,56]. The same trend of better results is seen when applying tools related to process function (PF): a 15% increase in rate of surviving shrimp after process quality control [53], reduction in processing lead-time [55,58,59,63,67], elimination of tasks and activities that do not add value to the product or process [63,64,65]; improvement in product quality [59,62]; modeling for optimization of results [5,60]; customer satisfaction [66]; reduction in production costs [61]; and reduction in losses and productivity impacts in a broad way [15,54,56].

The results allow us to identify that applying LP concepts in farms and cultures generates quality, customer satisfaction, economics, cost reduction, and productivity increments, among others. Through execution of this review, it becomes evident that LP concepts are applied in agriculture and cattle raising, with several applications and positive results. As observed, performance has been identified in shrimp, rice, milk, chicken, eggs, and vegetable crops—each one with specific characteristics, objectives, and results—leading us to conclude that, in general, the concepts can and should be applied to any production system given the diversity of its performance. We also point out that the tools used, for example, value stream mapping (VSM), layout, Karakuri Kaizen, standardization, visual management, experiment panel, problem-solving methods, product life cycle assessment, 5S, and SMED, contribute positively to resolution of the problem, acting in combination or isolated.

It is observed that many studies apply VSM. With this application, it is possible to interpret that, even with extremely positive results of application of LP concepts in agro-pastoral production, there is still an initial process of interpretation and mapping of the production flow, wherein continued application of the method and other lean tools will result in more elimination of losses and waste and a steady increase in the competitive factors of this type of organization.

Another evaluation concerns the impacts of applying the LP method concepts on the sustainability pillars. Considering the TBL model, it can be related to the lean concepts presented in

Table 7. Relationship between results and impact on TBL.

Results	Impacts on TBL 1	Publications
The increased shrimp survival rate	Economic and Environmental	[53]
Reduced lead time processing	Economic	[55,58,59,63,67]
Adherence to lean philosophy and tools	Economic and Social	[15,54,56,57]
Improved productivity rates	Economic and Social	[15,54,56]
Improved quality	Economic, social, and environmental	[59,62]
Customer satisfaction	Economic and social	[66]
Optimization of results	Economic	[5,60]
Elimination of non-value-added tasks and activities	Economic	[63,64,65]
Cost reduction	Economic and Social	[61]

¹ Impacts on TBL sustainability concept.

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It is possible to see the results presented in Table 7 and compare the improvements generated by applying LP concepts with the TBL pillars. Lean production (LP) positively impacts economic issues. However, even if the economic impact is more latent in some cases, it is also possible to consider the relationship between social and environmental impacts from the results presented using lean production concepts. For instance, more animals survive and product quality improves [53,59,62] with the environment, and better productivity rates and, consequently, lower sales prices [15,54,56] with application of the lean philosophy [15,54,56,57] and quality improvement [59,62] are relevant to society. Therefore, it can be stated that use of LP tools and concepts in farms generates positive results and impacts the organizations and TBL pillars.

The study found that lean production concepts can also have positive social impacts by improving working conditions and reducing labor costs. Moreover, lean production concepts have environmental impacts by reducing waste, minimizing energy consumption, and decreasing environmental pollution. Therefore, the study demonstrates the potential of using lean manufacturing concepts in agro-pastoral production to improve sustainability and provide practical examples and recommendations for implementing lean practices in agricultural operations aligned with sustainability.

4. Conclusions

The general objective of this research was to identify which tools associated with lean production (LP) are applied in agro-pastoral production, their impacts on reduction in losses and waste, and productivity increases considering the view of process function (PF), operation function (OF), and agro-pastoral production, relating them to a sustainability model based on TBL. Through a systematic review of the literature, it is possible to see that application of lean manufacturing (LM) concepts in agro-pastoral production is perceived in various ways and different types of crops and production, such as application of various tools derived from lean production (VSM, 5S, problem-solving, etc.) in vegetable crops, rice, livestock, shrimp, chicken, eggs, among others. There is a reduction in losses and waste with an increase in productivity in the studies evaluated, generating the perception that LM can easily adapt its concepts for application in agro-pastoral production. There are many future opportunities for application of lean concepts. It is possible to relate TBL pillars and application of LP concepts, highlighting the economic effects of using LP tools. Moreover, it is possible to notice the social and environmental impacts of applying LP concepts in agro-pastoral production.

The theoretical contributions of these studies and evaluations include identifying and applying various lean tools and techniques, such as VSM, Heijunka, and operations research modeling, in the agricultural sector. These tools and techniques can identify and eliminate non-value-adding activities, optimize logistics operations, and streamline decision-making processes, leading to increased productivity and profitability. Additionally, the studies provide insights into the effectiveness of implementing RFID technology in agricultural operations and use of eco-efficient schemes and equipment adjustments to reduce energy consumption and environmental impacts.

The practical contributions of these studies include provision of specific examples and case studies of successful lean implementation in the agricultural sector, such as survival rate and sales increase in shrimp farms, reduction in waiting time in post-harvest processes, reduction in losses in processes, and reduction in time in activities that do not add value. These practical examples can serve as a guide for other agricultural operations looking to implement lean practices. Additionally, the studies provide recommendations for improving adherence to lean principles and techniques, such as focusing on employee and partner engagement, and can be used as a benchmark for other agricultural operations to measure their performance.

The studies also provide a theoretical and practical understanding of how lean principles and techniques can be applied to the three pillars of the triple bottom line (TBL) framework: economic, social, and environmental. The economic pillar relates to focus on productivity and profitability. In contrast, the social pillar relates to emphasis on employee and partner engagement, and the environmental pillar relates to focus on reducing energy consumption and environmental impacts.

The research has limitations, such as sample size, and focuses on specific lean tools and techniques, which may only apply to some agricultural operations. The results may not be generalizable to other sectors and may need to account for other factors that can affect productivity and profitability in the agricultural sector. Another limitation is that the studies and evaluations presented need more practical implementation guidelines, resources, and obstacles information, which could make it difficult for other agricultural operations to replicate the successes reported in the studies. The articles focus on demonstrating the effectiveness of lean practices in the agricultural sector but do not provide clear instructions on how to apply these practices in other agricultural operations.

Finally, we cannot say there is a tendency to apply LM concepts in agro-pastoral production. However, it is possible to affirm that the process is still at an early stage, with a great perception of application of initial concepts of lean manufacturing, for example, VSM, 5S, and SMED, among others. This arrangement suggests a tendency for growth in the studied question, with possibilities of real conceptual evolution regarding the subject.