of Ergo al no rn m u ic o s J Roger et al., J Ergonomics 2018, 8:2 Journal of Ergonomics DOI: 10.4172/2165-7556.1000228 ISSN: 2165-7556 Research Article Article OpenOpen Access Access Ergonomic Testing for the Design of an Innovative Mail Delivery Vehicle: A Physical Mock-up Case Study Morgane Roger1, Nicolas Vignais1,2,3*, François Ranger1,4 and Jean-Claude Sagot1 1ERCOS, Université de Technologie de Belfort-Montbéliard, Site de Montbéliard, 90010 Belfort Cedex, France 2CIAMS, Universite Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France 3CIAMS, Université d’Orléans, 45067, Orléans, France 4Université du Québec à Montréal, Montréal, Québec, Canada Abstract The aim of this study was to provide ergonomic recommendations concerning passenger compartment dimensions of an innovative vehicle dedicated to mail delivery. To this aim, an ergonomic analysis of egress/ingress postures has been performed on a physical mock-up, which is considered as a reliable tool when investigating driving space. Six workers with different anthropometries participated to the experiment. The influence of three seat heights, two headlining heights and three headlining widths were tested while participants performed a simulated mail delivery task. Based on goniometers and video observations, a Rapid Entire Body Assessment (REBA) was conducted. Perceived discomfort was estimated with a Category Partitioning Scale (CP-50). Results showed that REBA scores were mainly at medium risk (5.18 ± 1.75). Discomfort scores were significantly influenced by seat height (χ2 (2) = 7.79, p = 0.02), especially for short participants when seat height was equal to 760 mm (Z = -2.21, p = 0.03). REBA scores and discomfort scores were significantly higher for the lowest headlining height and the highest headlining width. Outcomes of this study permitted to establish that: the seat height has to be adjustable (between 580 mm and 760 mm), the headlining height has to be fixed to 1360 mm, and the headlining width has to be comprised between 300 and 525 mm. The results from this research suggest that physical mock-up can provide a useful tool for defining suitable dimensions for the design of a future vehicle, taking into account anthropometric characteristics of the target population. Keywords: Physical ergonomics; Physical mock-up; Vehicle design; consuming method for obtaining postures in work simulation [13] as it Anthropometry significantly depends on the assessor’s abilities [14]. Introduction In parallel to DHM, physical mock-ups will appear to be a reliable tool in vehicle product development, especially when understanding The automotive industry is a lucrative but highly competitive the driving space and the act of getting in/out of the cab [15-18]. industry with more than 50 major manufacturers worldwide [1]. Thus, Contemporary physical mock-ups can be fully adjusted to various automotive manufacturers must quickly propose new products that vehicle interiors in order to evaluate usability and ergonomics before meet end-users’ needs to retain their share of sales in a contracting real products are manufactured. For example, Sang and colleagues market. [19] used a physical mock-up to test the impact of anthropometric Understanding and integrating the customer’s needs into a characteristics of a target population on vehicle design. Through product, so called user-centered design, provides functionality physical mock-up, researchers have been able to assess ergonomic into this product from which the user will derive benefits [2,3]. The aspects of the vehicle such as reachability, spatial perception and size principle of user-centered design states that “if an object, a system or estimation [20] and then turned it into industrial production. This tool an environment is intended for human use, then its design should be enabled designers to adopt an applied user-centered design approach based upon the physical and mental characteristics of it human users” as participants testing the physical mock-up are real and not virtual [4]. In the automotive context, this design process implies at some manikins. Moreover, physical mock-ups are considered as a reliable point, testing a prototype of the vehicle with various target users’ ergonomic technique into the International Standard ISO 6385 [21]. anthropometric characteristics to integrate suitable dimensions to the This Standard establishes the fundamental principles of ergonomics final product [5,6]. As it may appear difficult to recruit such various as basic guidelines for the design of optimal work systems in a user- participants directly in the field, International Standard ISO 15537 [5] centered design approach. It also recommends “to design a work also mentioned that digital human models (DHM) can be used through system for a broad range of the design population in order to meet this step. Integrating DHM into the industrial process has often been *Corresponding author: Nicolas Vignais, CIAMS, Université Paris-Sud, proposed as a strategy to design safer and efficient products while Université Paris-Saclay, 91405 Orsay Cedex, France, Tel: +33 169154703; E-mail: optimizing productivity and cost [7]. Indeed DHM supports the [email protected] ergonomic evaluation of new vehicle design during early stages of the Received March 04, 2018; Accepted March 21, 2018; Published March 30, 2018 process, by modelling anthropometry, posture, motion or predicting discomfort (see e.g. [8]). Nevertheless, it is necessary to accurately Citation: Roger M, Vignais N, Ranger F, Sagot JC (2018) Physical Ergonomic Testing for the Design of an Innovative Mail Delivery Vehicle: A Physical Mock-up posture the virtual manikin to effectively use DHM [9]. Some Case Study. J Ergonomics 7: 228. doi: 10.4172/2165-7556.1000228 researchers have demonstrated that large errors can occur when these Copyright: © 2018 Roger M, et al. This is an open-access article distributed under postures are compared to those adopted by workers performing the the terms of the Creative Commons Attribution License, which permits unrestricted actual task in their genuine physical environment [10-12]. Moreover, use, distribution, and reproduction in any medium, provided the original author and manipulating the virtual manikin has been identified as a time- source are credited. J Ergonomics, an open access journal ISSN: 2165-7556 Volume 8 • Issue 2 • 1000228 Citation: Roger M, Vignais N, Ranger F, Sagot JC (2018) Physical Ergonomic Testing for the Design of an Innovative Mail Delivery Vehicle: A Physical Mock-up Case Study. J Ergonomics 7: 228. doi: 10.4172/2165-7556.1000228 Page 2 of 9 the needs of workers with various characteristics, including people in the experiment (weight: 64.2 ± 12.4 kg; age: 43.8 ± 4.1 years; years with special requirements, as far as possible” (p. 3). More specifically, a of experience: 17.2 ± 6.8). These participants have been selected based mock-up is the foundation of the work on which communication and on the Standard ISO 15537 procedure about preliminary design collaboration are established between the various actors involved in the test [5]. When testing a free space dimension like HH and HW, this design process [22]. The present study then used a physical mock-up to standard mentions that participants should own to the 95th percentile. define ergonomic requirements to design a special vehicle dedicated to Conversely, when assessing a reaching dimension like the distance th mail delivery. between seat and wheel, participants should correspond to the 5 th Most mail carriers use cars, bicycles or walk to deliver mail along percentile. In the current study, although women were close to the 5 their route. When walking, slip, trip and fall accidents may occur percentile in height, men were much like the 95th percentile according [23,24]. Moreover, mail carriers can deliver 2500 letters per day on to the Belgium comparison population (Table 1) [27]. Thus, women average with a delivery period being 4 to 5 hours daily [25]. When and men have been respectively associated to anthropometric groups bicycling, the physiological demand is greatly increased, especially with G5 and G95, starting from the hypothesis that women and men would hilly geographical profile [26]. Moreover, when bicycling or walking, react similarly to go in and out of the vehicle. The study protocol was one of the main difficulties experienced by the operators is linked to the approved by the academic ethics board and all participants provided bag they use during their rounds. Through a functional and ergonomic informed written consent. study of load distribution with this kind of bag, Reinert and Lucio [25] showed that it is necessary to change the way of carrying mail during Materials delivery activity. For all these reasons, it appears necessary to conceive Multiscale physical mock-up for passenger compartment: A new ways to deliver mail. To avoid risks linked to walking and bicycling physical mock-up was used to simulate the future vehicle dedicated when delivering mail, the design of an ergonomic vehicle dedicated to to mail delivery (Figure 1a). This mock-up was composed of a fully this activity can be a solution. This vehicle will have to meet different adjustable aluminum structure where passenger compartment challenges: i) being compact and easy to handle, ii) providing enough elements, i.e. seat, wheel and gear lever, have been attached (Figure 1b). space for carrying a large amount of letters and packages, iii) permitting Elements of the aluminum structure may be adjusted for all degrees of to deliver mail quickly without getting out of the vehicle when possible, freedom in translation. iv) presenting an ergonomic access to the headlining area to improve ingress and egress postures when having to go out and into the vehicle. Camcorders: Four camcorders were placed around the physical The design of this innovative vehicle was part of the objective of the mock-up in order to film participants’ egress/ingress movements European Project MobyPost (http://mobypost-project.eu/) coordinated during the experimentation.