*Article* **Is the Shortest Path Always the Best? Analysis of General Demands of Indoor Navigation System for Shopping Malls**

**Hui Deng 1, Yiwen Xu <sup>1</sup> and Yichuan Deng 2,\***


**Abstract:** Indoor navigation systems are basic services for shopping malls. However, the design and implementation of such systems are seldom studied, with most current indoor navigation systems showing the static route for the shortest distance, which causes confusion or even danger for users. Therefore, this paper analyzes the general demand for indoor navigation systems for shopping malls based on 498 questionnaires and the Kano model. The results of the study unveil three important functions, as outlined by "Congestion/emergency section avoidance", "Vertical elevator first", and "Passing by a particular type of store". The relationship between users' characteristics and shopping behavior is also discovered. Comparing this with the existing literature in terms of user demands research for indoor navigation, the general demand analysis method based on the Kano model of this paper is able to reveal the user accreditation degree towards different functions of indoor navigation systems in shopping malls. The findings of this paper provide insight into users' behaviors and preferences, which will benefit further studies on indoor navigation systems for shopping malls.

**Keywords:** general demand analysis; Kano model; indoor navigation; system design

### **1. Introduction**

Indoor navigation systems realize the output of navigation paths in buildings through road network construction [1], indoor positioning [2], and path planning [3]. It is necessary and important to develop an indoor navigation system that reflects the general demands of users in shopping malls. Recently, many scholars have carried out independent research on the three important content factors of an indoor navigation system. In road network construction, IFC is a commonly used road network extraction method, combined with the BIM model [4,5]. In indoor positioning, Liu et al. [6] fused magnetic and visual sensors to study indoor localization without infrastructure, while Farahsari et al. [7] studied Internet of Things (IoT)-based indoor localization. In path planning, Deng et al. [8] studied path planning under fire evacuation scenarios, while Lee and Medioni [9] used an improved D\* algorithm to plan paths. However, at present, there is no mature indoor navigation system [10–12] that combines the three independent parts, and in particular, the existing indoor navigation systems do not really understand the users' demand, and there is no indoor navigation system that combines the users' general demand and dynamic environmental changes. At present, the visual navigation service only uses the fixed point where the LED display screen is located as the navigation starting point, and the user cannot navigate in real time on their mobile phone. The navigation service only provides the resulting output of the shortest path, and only a few shopping malls provide a personalized choice of priority vertical elevators or priority horizontal escalators, without considering environmental changes (such as congestion and emergencies) and their impact on user navigation experience and satisfaction. This leads to user dissatisfaction with indoor navigation deficiency. Users often find that the positioning of the navigation is inaccurate, the planned shortest route is congested, the traffic time is wasted, and navigation in the

**Citation:** Deng, H.; Xu, Y.; Deng, Y. Is the Shortest Path Always the Best? Analysis of General Demands of Indoor Navigation System for Shopping Malls. *Buildings* **2022**, *12*, 1574. https://doi.org/10.3390/ buildings12101574

Academic Editor: Ricardo M. S. F. Almeida

Received: 6 September 2022 Accepted: 26 September 2022 Published: 30 September 2022

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**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

vertical direction is not clear. The reason for these existing affairs and problems is that the indoor navigation system has not undergone an adequate demand functional analysis. As a functional service system for space management and operation and maintenance management, the indoor navigation system is used by "people" with independent will. Therefore, it is not enough for designers to only satisfy the planning of the shortest path between the start point and the end point. Only by conducting sufficient user research and demand analysis can the indoor navigation system achieve the greatest practical role and meet the individual needs of users.

In general, existing indoor navigation systems of shopping malls have problems such as ignoring the general demand of users and ignoring the dynamic changes of the scene. The lack of a complete survey for demand analysis of indoor navigation in shopping malls is, thus, the key issue to be resolved. General demand analysis has been proven to be the key starting point of system design, with successful examples such as industrial energy demand models [13], cooling demand models to design cooling systems for large office buildings [14], and hotel room demand analysis, which changed the direction of the hospitality industry [15]. However, there is a gap in the effective analysis of the general demand for indoor navigation systems.

There are several mainstream models for demand analysis, including Maslow's hierarchy of needs [16], SWOT analysis [17], the Boston matrix [18], and PEST analysis [19]. Among them, Maslow's Hierarchy of Needs method divides people's needs into five levels, physiology, safety, emotional belonging, respect, and self-realization, which is suitable for determining the macro function of products, such as designing internet products with the function of making friends out of emotional belonging. SWOT analysis divides events into four dimensions, strengths, weaknesses, opportunities, and threats, and constructs a matrix to facilitate the design of product positioning and competitive strategies. The Boston Matrix divides products into four categories, star category, thin dog category, problem category, and golden bull category, which is helpful for sales strategy adjustment. The PEST analysis method obtains the macro-environmental analysis of the product through the analysis of the political environment, economic environment, social environment, and technical environment. Compared with these methods, the Kano model is another important model that better suits the purpose of the study. The Kano model is a theory invented and proposed by Professor N. Kano in 1984. With its essence of reflecting the nonlinear relationship between satisfaction and performance [20], the model can classify and rank the demand of users. The Kano model helps to increase the value of a system or product, and will focus on the service design, development and verification phases, and functional design by real customers in the development design phase [21]. Integrating the Kano model into existing design methods can improve users' satisfaction with product design [22]. At present, the Kano model has been fully applied and studied in various aspects such as product development and the healthcare industry. Asian et al. [20] used this model to study the effective variables of third-party logistics providers in the automobile manufacturing industry. Hashim and Dawal [23] improved ergonomic design with the help of the Kano model. Li et al. [3] studied the user needs of an eco-city based on the Kano model. Materla et al. [24] summarized the application of the Kano model in the healthcare industry. However, no report on the application of the Kano model in the building operation and maintenance management stage has been found, especially in the design of indoor navigation products in shopping malls.

In order to fill the gap in which there is a lack of effective general demand analysis for indoor navigation, which causes deviation between the functions of the indoor navigation system and the user's general demand, this paper uses the Kano model with 498 questionnaires to determine the priority of different general demands in the functional design for indoor navigation in shopping malls. The design of a shopping mall indoor navigation system based on users' general demand and dynamic environmental changes is also proposed to inspire future designers for related products. The main contribution of this paper is to apply the Kano model, for the first time, to determine the general demand and

functions of indoor navigation in shopping malls. Existing research (Table 1) on user demand analysis of indoor navigation systems has mostly focused on the navigation needs of special populations [25,26], and mobility needs in the navigation process [27,28]. Compared to the existing literature in terms of user demand research for indoor navigation, the general demand analysis method based on the Kano model in this paper is able to reveal the user accreditation degree of the different functions of indoor navigation systems in shopping malls and meet the general demand of most people. Furthermore, the findings of this paper provide insight into users' behaviors and preferences from questionnaire research, which will benefit further studies on indoor navigation systems for shopping malls.


**Table 1.** Comparison between the method in this paper and the existing research.

The following is a summary of the framework of this paper. Section 2 describes the Kano model and the related evaluation indicators. Section 3 presents the results of the questionnaire survey, including the analysis of the basic information of the questionnaire, the correlation analysis, and the related indicators of the Kano model. Section 4 is a practical implementation of the general demand for an indoor navigation system in shopping malls, which is based on the results of Section 3.

#### **2. Materials and Methods**

The method used in this paper is shown in Figure 1, which mainly includes literature research, offline interviews, and questionnaire research. Through literature research and offline interviews, several major functions of general demand can be initially considered in the indoor navigation of shopping malls, as well as related qualitative indicators. Except for a few customers who are particularly familiar with shopping malls, most customers have high indoor navigation demands. Zhou et al. [29] considered path complexity, congestion, and blocking events when planning indoor paths. Basu et al. [30] believe that the Pedestrian Route Choice (PRC) needs to consider the relationship between perceptual factors and objective factors. The qualitative indicators mentioned here are mainly crowd-density indicators and traffic-speed indicators. Based on the above discussion, this paper identifies five general demands (2.1 Identify 5 general demands), namely "Avoid crowded/emergency roads", "Passing by specific types of shops", "Bypass specific types of shops", "Vertical elevator first", and "Escalator first". Next, we outline the questionnaire design based on these five general demands. The questionnaire is divided into three parts, including the basic personal information of users, objective data of users related to the indoor navigation of shopping malls, and subjective data of users. Due to the COVID-19 pandemic, this questionnaire was collected online. After obtaining the results of the questionnaire research, the analysis work was carried out. The reliability, validity, and correlation were tested, and the Kano model and related evaluation indicators were introduced. The types of general demands and the priority of consideration were determined through Kano model classification, mixed class, and coefficient analysis. A design of the indoor navigation

system of a shopping mall incorporating general demands identified from the results is presented to show how the conclusions drawn by the Kano model can be applied to the system design.

**Figure 1.** Method of this paper.
