Simulation of product lead time in design customization service for better customer satisfaction T. Hara *, T. Arai (1) Department of Precision Engineering, The University of Tokyo, Tokyo 113-8656, Japan 1. Introduction Globalization coupled with product customization and short time to market has spearheaded new levels of competition among manufacturers [1]. Improving product lead time has been a key issue in product development area on one hand. A number of process modeling approaches have been applied to product design in engineering domains for the shorter lead time [2]. On the other hand, manufacturers seek customers’ satisfaction by increasing product variety and by improving customization while striving for agility and productivity [3]. Design customization of products is a variable service process involving interactions with individual customers to better meet their needs and preferences. Such processes need to be validated from the customer’s viewpoint in addition to the variability analysis of product lead time. Process validation is usually conducted in the context of a system including design control, quality assurance, process control, and corrective and preventive action [1]. This paper deals with service interaction with customers as such a system to be validated in a design customization service. Studies on service, which originally began in the field of marketing, are nowadays seen as being more important issues in the manufacturing industry and product development. This background motivates many researchers to study Product/ Service-System (PSS) [4] or service engineering [5]. Although considerable software has being developed focusing on each domain, no integrated environment is available to use such deliverables. Toward a holistic computer-aided design system for service, this paper combines a method of process simulation for product development with a method of service modeling the authors have been working on. The rest of the paper is organized as follows. Section 2 explains early studies on evaluation of customer satisfaction. This paper focuses on customer satisfaction with design and production process such as delivery time in a personalized bag service, not with quality of customized bags itself. Section 3 illustrates technical mapping between two powerful methods of process modeling so as to enable process simulation of services. In Section 4, a process simulation about the personalized bag service is discussed. Section 5 concludes the paper. 2. Early studies on customer satisfaction This section explains studies on customer satisfaction (CS in short) that should be studied as an indicator of process validation of service. In general, CS is evaluated in two approaches: to do questionnaires directly to customers as a part of marketing activity, and to estimate CS based on service performance as an engineering activity. The most typical index on customer satisfaction, as an example of the former, would be ‘The American Customer Satisfaction Index (ACSI)’ [6] which employs difference between service performance and customer’s expectation. Regarding the latter approach, two theories would be famous: KANO model [7] in the field of product design, and prospect theory [8] in that of behavioral economics. These ideas are represented as nonlinear satisfaction functions. Kimita et al. [9] constructed concrete satisfaction functions by means of combining these two studies. The basic function is expressed in the following Eq. (1), where v expresses the value of a factor of service, a expresses maximum or minimum CS regarding the factor, b expresses customers’ sensitivity to the factor, and c expresses the value of expectation of the factor. S r ¼ a 1  e  b a ðvcÞ n o (1) CIRP Annals - Manufacturing Technology 60 (2011) 179–182 ARTICLE INFO Keywords: Design Simulation Service ABSTRACT Services differ from products as the former should be evaluated from a customer’s perspective. For better customer satisfaction, simulation of order processing service such as design customization needs to analyze customer’s behavior in addition to the evaluation of product lead time. In this paper, we model and simulate service processes of a design customization about personalized bags by combining two kinds of powerful software from services and design processes. This simulation estimates its product lead time in terms of customer expectation that is formed according to provider’s strategies. As a consequence, variability of customer satisfaction of the service is analyzed. ß 2011 CIRP. * Corresponding author. E-mail address: hara_tatsu@robot.t.u-tokyo.ac.jp (T. Hara). Contents lists available at ScienceDirect CIRP Annals - Manufacturing Technology journal homepage: http://ees.elsevier.com/cirp/default.asp 0007-8506/$ – see front matter ß 2011 CIRP. doi:10.1016/j.cirp.2011.03.092