A Green Cooperative Development Method Based on the IDEF0 Model of Manufacturing Knowledge: Case Study of a Carton-Filling Machine

Abstract

This is a case study of cooperative development between a college and a corporation to manufacture a carton-filling machine. Specifically, a green cooperative development method was proposed that would match the college’s design capabilities with the manufacturing capacity of the enterprise. This college–enterprise cooperative development represents an extensive collaboration between industry and academia. This method integrates design for manufacturing (DFM) theory and the integrated computer aided manufacturing definition (IDEF) method to establish the IDEF0 (functional) model of manufacturing knowledge that supports the design process. The model clarifies the specific manufacturing knowledge that enterprises should provide at the conceptual design stage, preliminary design stage and detailed design stage. The forms of communication and timing of knowledge provision needed to optimize development planning and design decisions based on the manufacturing capacity of the enterprise were also determined. Through this method, the college–enterprise cooperative development project (in this case, involving a carton-filling machine) was accomplished with less time, fewer design modifications and fewer parts needing to be reworked. The results show that this method can greatly reduce the run-in period of both parties, improve the efficiency of cooperative development and reduce the cost and waste of prototyping.

1. Introduction

College–enterprise cooperative product development is mutually beneficial for the college and enterprise as it synergizes development of education and industry [1,2,3]. This business model is developing rapidly in China, since product design plays an increasingly prominent role in enterprise competition [4,5]. To maximize the advantages of both sides, the college is generally entrusted to design the products, and the enterprise manufactures them. In the process of college–enterprise cooperative development, it is likely that the college’s design will be disconnected from the manufacturing conditions of the enterprise, especially in the first cooperative exercise. Unfortunately, this disconnection may lead to the need for many modifications or even redesign, which may greatly increase the cost of prototyping. To solve this problem, we carried out a case study of college–enterprise cooperative development to produce a carton-filling machine, and we proposed a green development method. This paper focuses on improving the management of the cooperative process by constructing a manufacturing knowledge functional (IDEF0) model to support the cooperative development process by integrating design for manufacturability (DFM) theory and IDEF0 methods.

Sustainable development is a long-term green development model that can be steadily improved. In the process of mechanical equipment development, the idea of sustainable development is widely used to guide design and manufacturing and continuously improve organizational performance. Rathi et al. [6] identified 23 success factors of Green Lean Six Sigma (GLSS) from the literature pertaining to manufacturing and found that management and finance-related issues are the most significant critical success factors for improving organizational performance. The same conclusion was reached in their other research regarding a GLSS success factor analysis of Indian medical institutions [7]. Recently, they established a framework for integrating GLSS and Industry 4.0 to improve the sustainability of an organization [8]. The IDEF0 method is widely used for the process analysis and optimization of organizational activities. Gu [9] used IDEF0 to improve the teaching process of information systems analysis and design. Li et al. [10] used the IDEF0 model to optimize the collaborative distribution of agricultural products under cloud logistics. Lu [11] used the IDEF0 method to direct the design and development of ship-loading fasteners. These researchers all achieved improved results.

Sun et al. [12] emphasized the importance of manufacturing knowledge to the design process, analyzed the tasks and manufacturing knowledge required in each stage of product design, and built a manufacturing knowledge IDEF0 model for the product design process. In large-scale production or mature process conditions, the methods and technologies of design for manufacturing (DFM) or design for manufacture and assembly (DFMA) are widely used to reduce manufacturing costs and improve product performance by promoting the easy design and manufacturing of products [13,14,15,16]. While most of the literature describes successful application cases of DFM, Budinoff et al. [17] used negative personal design experiences to emphasize the consideration of manufacturing constraints for hardware startups. In order to better support product design decision making and design innovation, many researchers continue to carry out research on manufacturing knowledge sharing [18], manufacturing knowledge modeling [19], manufacturing knowledge management [20], and the system integration of manufacturing knowledge [21]. The knowledge of different manufacturing processes refers to machine and process capabilities, and the latest technological developments are expressed through a reasonable structural model. Through the manufacturing knowledge retrieval system, the sharing of manufacturing knowledge is promoted, the knowledge transfer process is accelerated, and the overall manufacturing technology level is improved. Extensive integration of social technology systems is carried out in the manufacturing fields of aviation, shipbuilding, etc.

The above research conclusions regarding the key factors of organizational performance improvement as well as the application of DFM and IDEF0 methods in sustainable development are all based on the industry itself; colleges have not appeared as relevant parties, since they are not part of the manufacturing industry. When colleges directly participate in manufacturing activities, it is important to ensure that the cooperative parties communicate effectively and carry out cooperative activities smoothly, matching their design with manufacturing to improve the success of cooperative development. Building on the above research, this paper proposes a new, green method for cooperative development based on a case study of a carton-filling machine designed and engineered by a college team and a manufacturing team used to produce and build mechanical equipment.

2. IDEF0 Model of Manufacturing Knowledge That Supports the Design Process

2.1. Design Process and Manufacturing Knowledge Requirements

Mechanical design is a complex process that generally follows the model of "Design–Evaluate–Redesign" [22]. The whole process is divided into three main design stages: conceptual design, preliminary design and detailed design. The design starts with determination of the principal solution based on requirements, the product structure and general layout, and finally, the precise shape of the product [23], which must accommodate the application of various elements of manufacturing knowledge.

In a broad sense, manufacturing knowledge refers to all knowledge related to manufacturing in the whole life cycle of products, including the six aspects of staff, equipment, material, manufacturing method, manufacturing environment and measurement [24]. These aspects all come from the manufacturing workplace and have a strong constraining effect on design activities. The manufacturing knowledge relevant to the different design processes must be available to the engineers well in advance of design inception [25]. The design decisions in different design stages require various levels of manufacturing knowledge, with the later stages needing more detailed and varied manufacturing knowledge for design decisions. Other parts of manufacturing knowledge are needed throughout the whole design process. Figure 1 shows the design decisions that need to be made at each stage and the manufacturing knowledge that needs to be used to make them.

2.2. IDEF0 Model That Support the Design Process

IDEF0 is a systematic menu tool developed on the basis of structural analysis and design technology. It can simultaneously express system activities (represented by boxes), data flows (represented by arrows), and their interrelationships. The arrows generally indicate input, output, control and mechanisms. The IDEF0 model consists of these graphic symbols, and natural language is used to express the logical sequential relationship between the various design elements in the design process [26,27,28]. As shown in Figure 2, the input (I) represents the relevant parameters and data of the design process; the output (O) is the design outcome; the control (C) is the design guidelines and requirements; and the mechanism (M) is the necessary manufacturing knowledge in the design process.

As shown in Figure 3, by applying a top-down structured analysis to the three stages of the design process and clarifying the design–decision relationship of each stage, we can obtain an IDEF0 decomposition model diagram of the design process.

2.3. IDEF0 Model of Manufacturing Knowledge for College-Enterprise Collaborative Design Decisions

In college–enterprise cooperative development of a mechanical product design, the college has strong design capabilities, whereas the enterprise possesses a large amount of product manufacturing knowledge and capacity [29]. Each of the two sides uses their advantages to develop a machine from a project design. In conventional college–enterprise cooperative development, the relative stability of factors, such as workplace, process, equipment, technical conditions, staff, supplier, etc., usually results in many restrictions on the design. As a result, the enterprise’s manufacturing knowledge has a significant impact on design decisions in the design process. Considering the above characteristics, the A0 diagram of the manufacturing knowledge IDEF0 model for college–enterprise collaborative design decisions can be constructed, as shown in Figure 4.

3. IDEF0 Model of Manufacturing Knowledge Building for the Development of a Carton Filling Machine

3.1. Overall Goals and Requirements of the Carton Filling Machine

This study demonstrates the initial cooperative project of a college and enterprise to develop a product, in particular, a carton-filling machine that will package cartons of cigarettes. The college team has rich experience in developing packaging equipment and relevant experience in tobacco packaging equipment design; the enterprise has a long history of experience in manufacturing equipment for the tobacco industry. The machine will be designed to meet the needs of a third party, specifically, to fill double-layer fixed cartons with 10 packed small boxes of cigarettes. Neither the small boxes nor the cartons are supplied pre-assembled online, and only one operator is assigned to operate the machine in production. The machine needs to perform the following operations: automatically supply/deliver the carton; open the carton; turn the sulphate paper; remove the desiccant; print the inkjet code on the cigarette carton; feed, position and fill the carton; turn the sulphate paper back; and close the carton. The machine requires a running speed of no less than 12 strips/minute and a high motion accuracy to ensure that no surface scratches appear on the cigarette cases and cartons in the filling process. In addition, the use of industrial robots for filling and multi-station visual inspection is required. The overall process flow is shown in Figure 5. The development cycle is a particular concern to the enterprise in this college–enterprise cooperative development. The entire process, from contract signing and scheme design to the completion of assembly and commissioning, needs to be completed within 150 days, so the third-party enterprise can put the machine into production as planned.

3.2. IDEF0 Model of Manufacturing Knowledge-Building for Cooperative Development

The diagram shown in Figure 6 is an IDEF0 model of manufacturing knowledge for the design process of the carton-filling machine. The IDEF0 model outlines the design knowledge and manufacturing knowledge required for the various stages of the carton-filling machine design. In the college–enterprise cooperation, enterprises should sort the relevant manufacturing knowledge at each stage as early as possible and provide it to the designers to ensure better design decisions.

3.3. IDEF0 Model of Manufacturing Knowledge for the Key Component

The positioning and filling device, one of the functional modules of the carton-filling machine, is a key component, performing three operations: carton positioning, carton filling and filling detection. The ability to achieve precise positioning and fast, non-destructive filling is crucial for the success and performance of the whole machine. Taking this key component as an example, the manufacturing knowledge required at each stage of design is completely deconstructed through the IDEF0 model. To highlight the basic role of manufacturing knowledge in the process of college–enterprise cooperation, an IDEF0 model for key devices is essential. Figure 7 provides a detailed description of the manufacturing knowledge as well as a general description of the design knowledge needed at each design stage.

In the development process of college–enterprise cooperation, there should be detailed exchanges at the conceptual design stage about the experience that the enterprise has in relevant technical fields to avoid unnecessary exploration of a technical route. At the conceptual design stage of this product development, the basic technical route was quickly decided based largely on the manufacturer’s previous cigarette packaging equipment experience. The enterprise generally has its own preferred or designated suppliers of some common components and parts, so the designer should give preference to product models within this supplier system. Some important functional components are often appointed by the enterprise and need to be identified ahead of the detailed design phase.

4. Process Control Based on the IDEF0 Model of Manufacturing Knowledge

4.1. Building the College–Enterprise Development Team Based on the IDEF0 Model of Manufacturing Knowledge

According to the needs of manufacturing knowledge listed in the IDEF0 model, both sides of the cooperative development carried out an analysis of their advantages and limitations. The enterprise had experience in the development of products, such as a small cigarette box demolding machine, small cigarette box forming machine and single-opening strip box forming machine. The enterprise also had rich experience in robotics and visual inspection. The college team had outstanding advantages in the development of mechanical systems and paper packaging automation equipment but was relatively inexperienced in the programming and debugging of automatic control systems. Therefore, the participation of the relevant technical staff from the enterprise was needed for the effective promotion of the cooperative development process.

The two sides agreed that the college would be responsible for the development of the mechanical system, and the enterprise would be responsible for the development of the control system. The enterprise provided one manufacturing engineer to join the design team and participate in the whole design process. This engineer was in charge of providing the enterprise’s manufacturing knowledge as required at every design stage. The enterprise also provided one control engineer to join in the detailed design stage.

One green aspect of the design of the college–enterprise cooperative was to realize sustainable fostering of applied technological talents. Therefore, the development team invited three graduate students to participate in the development of the project. Due to time constraints, the participating graduate students were selected according to their ability to undertake part of the project independently after simple training. The students participated in the visits and exchanges between the two sides from the beginning and undertook part of the drawing work after entering the detailed design stage. They also participated throughout the assembly and commissioning work, being responsible for the pre-assembly of simple parts and recording problems in the assembly and commissioning of parts.

4.2. Communication of Manufacturing Technologies and Conditions Based on the IDEF0 Model of Manufacturing Knowledge

According to the IDEF0 model of manufacturing knowledge, the enterprise gave a clear disclosure of their manufacturing technology and hardware and software capabilities, submitting the relevant technical documents simultaneously.

At the beginning of the project, key participants from both the college and manufacturer visited the production site of the tobacco enterprise that would use the machine and gained a detailed understanding of the user’s technical requirements. The enterprise then led the college designers to visit their own processing and assembly workshops. After detailed discussions about the site conditions, process and equipment, the designers gained a comprehensive understanding of the enterprise’s own processing capacity, processing accuracy, manufacturing cycle, and especially the constraints of hoisting conditions in the debugging workshop on the overall size of machinery. They also gained a basic understanding of the number, skill level and operational efficiency of the commissioning technicians.

After completing the conceptual design, the documents (including the application specifications of standard parts, the supplier’s list of outsourcing parts and the list of commonly used materials) were sorted by the enterprise and provided to the designers, so the designers could prioritize using the available resources as much as possible, without incurring additional costs of supplier expansion and parts stock. These documents also facilitated the rapid commissioning of replacement parts if modifications were needed.

Next, the two sides held an experience exchange meeting about common problems encountered in the past debugging of similar equipment assemblies. Many problem prevention methods and improvement measures were proposed to avoid repeating past mistakes and to reduce the time taken in the manufacturing and assembly cycle.

4.3. Design Process Control

Based on the historical experience of collaborative development, the designers estimated the development cycle of this project would be no less than 150 working days, exceeding the time frame requested by the client company. Therefore, we re-evaluated the entire project and planned the development process in detail using on the IDEF0 model. We were finally able to set the development cycle at 120 working days. The time allotted for tasks was planned in four stages: conceptual design stage, preliminary design stage, detailed design stage, and assembly and commissioning stage, with a basic time unit of six days per week, as shown in Figure 8.

We focused on optimizing the project in periods of phased scheme design and detailed design as follows:

(1) Optimization of the phased scheme review activities: Many review activities concentrated on the late conceptual design stage and the late preliminary design stage. General technical discussions were held online. Only the reviews of the principle, technical proposal and the detailed design program were held face-to-face between the college and the enterprise (marked by ▲ in Figure 8). In the first stage, there were three centralized activities carried out by technicians from both sides. The first activity was completely based on manufacturing technology exchange. The other two project reviews included as many enterprise engineers and technicians as possible, especially those who had experience in the development of relevant machines. The engineers and technicians fully critiqued the proposed design scheme from the manufacturing perspective. All useful opinions were widely accepted by the designer team to avoid manufacturing defects in the design scheme. This greatly improved the manufacturing friendliness of the design.

(2) Optimization of detailed design activities: Based on the knowledge of corporate manufacturing, we finished the engineering design of the components in groups according to the length of the processing cycle and procurement cycle at the detailed design stage. We abandoned the traditional engineering design approach of functional module by functional module. The whole detailed design process was divided into six sub-stages according to the length of the processing cycle. The parts with long machining cycles or long lead times were designed first—the longer the cycle, the earlier the design. For particularly long lead times and problem-prone parts, a buffer period was reserved. This ensured that the last batch of parts scheduled for production could be completed in almost the same time as the previously designed parts. At the stage of detailed design activities, the graduate students played a complete role, since they undertook much of the engineering drawing work. Because the graduate students had a complete grasp of relevant manufacturing knowledge in the early stage, the engineering drawings they produced were correct and in line with standards.

5. Results and Discussion

By utilizing the IDEF0 model of manufacturing knowledge, the college and the enterprise strengthened their communication. By clearly understanding the interrelationships in each design stage, the three stages of the design process were completed on schedule. The overall structure of the box filling machine is shown in Figure 9. According to the workshop conditions and hoisting and transportation capacity of the enterprise, the main body of the machine was divided into three sections. This greatly sped up the assembly process, since the three groups carried out assembly operations at the same time, and the final machine assembly was completed 2 days in advance. The main body of the machine had 256 machined parts in total. The structures and dimensions were each carefully designed according to the manufacturing capacity of the enterprise, and only six parts (2.3%) were redesigned for being beyond the processing capacity of the enterprise. In comparison, the previous similar machine that the enterprise and another college developed in cooperation had 20 redesigned parts, accounting for 9.5% of the total 210 machined parts. Moreover, compared with the addition of two suppliers in the previous similar machine development, no suppliers were added in this case. Reasonable selection of part materials, purchasing parts according to the common suppliers list of the enterprise, and utilizing a large number of purchased parts in stock accounted for 20% of the total purchased parts in this case, which helped the enterprise to effectively reduce their inventory. The surface treatment of parts was handled, together with other product parts, by adopting the same treatment process of the enterprise, which also reduced the environmental pollution and manufacturing costs.

In the testing stage of the materials, some functional problems were discovered, and the functional units were modified. The modifications involved multiple core functional components. A total of 12 parts were modified and processed into a total of 26 pieces. Since all parts could be modified by the enterprise on site, the enterprise arranged processing and production immediately after the college team submitted the modified drawings. The modification project was rapidly advanced, and after several days of material commissioning, the machine met the user’s requirements. Figure 10 shows the local prototype of the carton-filling machine and the filled carton. It took 135 days to complete all the development tasks, saving 10% of the time compared to the traditional timeline of 150 days. The manufacturing cost was RMB 176,000, a savings of 12% of the manufacturing budget of RMB 200,000. A comprehensive comparison of the benefits of the new method is shown in

Table 1. Comprehensive comparison of the benefits of the new method.

Item	Budget	Actuality	Past Similar Case	This Case	Effect
Assembly days	20	18	/	/	−10%
Parts redesign (%)	/	/	9.5	2.3	−75.8%
Added suppliers	/	/	1	0	/
Stock usage (%)	/	/	8	20	+150%
Total project days	150	135	/	/	−10%
Cost (RMB)	200,000	176,000	/	/	−12%

.

In addition to the benefits directly related to the design and manufacturing process, subsequent transportation and delivery operations were also easier and cheaper, due to giving full consideration to lifting and transportation requirements. The machine needed to be transported more than 1100 kilometers from Wuhan to Chengdu, where it was installed for production. The reasonable segmented structure design enabled the equipment to be disassembled into three parts and rearranged accordingly on the back of an open truck, so that transportation could be successfully completed with only one truck. If the machine had been transported as a whole, it would have needed to be transported by a flatbed truck because the overall width of the machine exceeded the width of the ordinary truck, which would greatly increase the cost of long-distance transportation. After arriving at the destination, only the forklifts owned by the customer’s enterprise were used to complete the unloading and moving of the machine parts, without the need to hire a large crane, which was also more cost-effective.

6. Conclusions

This paper describes a green design method for a carton-filling machine. Two partners adopted the ideas of the DFM and IDEF0 methods to establish the IDEF0 model, which defined the manufacturing knowledge required at each stage of the product design. The enterprise provided the necessary manufacturing knowledge to the college in a timely manner through a variety of appropriate methods, so the design plan and decision making were always based on the enterprise’s manufacturing capacity.

This case shows that the IDEF0 model of manufacturing knowledge can play a vital role in the communication and process management of cooperative development between college and enterprise. The model ensures that the design is well matched with the manufacturing capability of the enterprise, improves the development success rate, shortens the cooperative development cycle, and reduces waste and loss caused by redesign and remanufacture. It is a green design method for improving the cooperative performance of mechanical development between colleges and enterprises, especially for a designer who emphasizes theory.

Because contradiction between design and manufacturing teams is common in all cooperative development processes (not only between colleges and enterprises), it is necessary to find a universal method to solve this problem. The method proposed in this paper shows promising results in the case described and needs to be verified by more applications. The process should be continuously improved to be more widely adaptable to guide various cooperative developments in the field of manufacturing.