APEM jowatal Advances in Production Engineering & Management Volume 12 | Number 3 | September 2017 | pp 265-273 https://doi.Org/10.14743/apem2017.3.257 ISSN 1854-6250 Journal home: apem-journal.org Original scientific paper Simulation of collaborative product development knowledge diffusion using a new cellular automata approach Kunpeng, Y.a, Jiafu, S.b*, Hui, H.b aManagemengt College of Ocean University of China, Qingdao, P.R. China bChongqing Technology and Business University, Chongqing Key Laboratory of Electronic Commerce & Supply Chain System, Chongqing, P.R. China A B S T R A C T A R T I C L E I N F O In order to quantitatively examine the diffusion process and pattern of collaborative product development (CPD), this paper puts forward a quantitative research model of CPD knowledge diffusion based on improved cellular automata. In light of the idea of SIS epidemic model and the local knowledge interaction characteristic of CPD knowledge diffusion, the influencing factors of knowledge diffusion are abstracted into the parametric variables in the process of knowledge diffusion, and the knowledge-SIS (K-SIS) model is constructed based on improved cellular automata for CPD knowledge diffusion. Finally, the K-SIS model is simulated to study the diffusion process and pattern of CPD knowledge, revealing the influence mechanism of CPD knowledge diffusion influencing factors on the diffusion process. The research results provide valuable reference for improving the efficiency of CPD knowledge diffusion. © 2017 PEI, University of Maribor. All rights reserved. Keywords: Collaborative product development Knowledge diffusion Influencing factors Cellular automata *Corresponding author: jiafu.su@hotmail.com (Jiafu, S.) Article history: Received 19 June 2017 Revised 30 June 2017 Accepted 2 July 2017 1. Introduction With the increasingly fierce competition in the product market, especially IT industry, pharmaceutical industry and automobile industry, enterprises are attaching more importance to the integration of suppliers, customers and other potential collaborators into product development. Owing to the deep integration of the collaborators' knowledge, collaborative product development (CPD) has become an new product innovation mode practiced by many enterprises, such as Apple, Xiaomi and LEGO, etc. The collaborative product development system (CPDS) consists of such collaborative members as suppliers, customers, other potential collaborators and enterprise professional product developers. Knowledge exchange and diffusion are prevalent in the CPDS owing to the asymmetry of the members in the structure of collaborative production development knowledge (CPD knowledge) and imbalance between them in the level of knowledge stock [1]. CPD knowledge diffusion enables each member to fully access and acquire the knowledge of others, thereby increasing the CPD knowledge stock of individual member and the entire CPDS. Meanwhile, the diffusion of CPD knowledge helps the members complement each other's advantages through the diffusion of CPD knowledge, optimizes the allocation of CPD knowledge resource, enhances the technical content of the CPD and accelerate the process of knowledge innovation and product development [2]. Therefore, the efficient knowledge diffusion opens up an important way to improve the product development capacity of the enterprises, and provides a key support to the successful development of new products. 265 Kunpeng, Jiafu, Hui As an integral part of knowledge management, knowledge diffusion has been followed and studied by many scholars. Probing into the effect of social cohesion and network size on knowledge diffusion, Reagans and McEvily argue that it is easier to diffuse knowledge if the members of society keep closer ties and shorter distances [3]. Kim and Park explore the relationship between the structure of collaborative organization network and knowledge diffusion, suggesting that the small-world network is the most fair and efficient collaborative network structure for knowledge diffusion [4]. Setting out from the motive and impetus to knowledge diffusion, Li et al. point out that the knowledge potential is an important determinant of the speed and breadth of knowledge diffusion [5]. Based on the philosophy of epidemiology, Bass establishes the "epidemic" model innovation diffusion, and expresses the model with mathematical equations [6]. From the perspective of NW small-world network, Sun and Wei build the knowledge diffusion model of high-tech enterprise alliance, and explore the effect of network clustering coefficient, characteristic path length and exchange frequency on the knowledge diffusion of the enterprise alliance [7]. Meng et al. adopt the multi-agent model of disease transmission to simulate the knowledge diffusion process in the network environment [8]. Focusing on the influencing factors, processes and models of knowledge diffusion, the above-mentioned literatures share two common defects: Firstly, most of them concentrate on the social network, the interior and exterior of enterprises, industrial clusters, R & D team, etc. but few pays attention to the diffusion of product development knowledge in the collaboration environment (e.g. CPDS). Secondly, based on mathematical methods, system dynamics and other theoretical methods, the majority of knowledge diffusion models lay too much stress on the macro features like the speed and process of knowledge diffusion, and largely ignore the microscopic basis that the knowledge diffusion is the result of the knowledge activities between the knowledge subjects. Knowledge diffusion is a complex process in which organized and complex knowledge behaviors are formed through the local knowledge interaction between the knowledge subjects [9]. In light of the above, this paper intends to study the CPD knowledge diffusion by the complex system modeling method: cellular automata (CA). Targeted at the complex and inenarrable process of CPD knowledge diffusion, the author draws on the idea of SIS epidemic model, describes the knowledge exchange activities between knowledge subjects and collaborative teams, and illustrates the macro knowledge diffusion phenomenon of the entire CPDS. From the micro-level to the macro-scale, the description and illustration are clear and intuitive. On this basis, the traditional CA model is improved, and the quantitative model of CPD knowledge diffusion is constructed based on improved CA. The model is used to examine the process and pattern of CPD knowledge diffusion, revealing the influence mechanism of CPD knowledge diffusion influencing factors on the diffusion process. This paper aims to quantitatively analyze the CPD knowledge diffusion process and effectively predict the diffusion trend, which can help managers to better improve the management performance of CPD. 2. Analysis of CPD knowledge diffusion process Knowledge diffusion refers to the transfer and sharing of knowledge between different subjects across time and space. In the context of CPD, the knowledge in the CPDS is diffused between different knowledge subjects, between knowledge subjects and collaborative teams, and between different collaborative teams [10, 11]. During the diffusion of CPD knowledge, the knowledge exchange happens between knowledge receivers and knowledge transmitters. Based on their own demand of knowledge and understanding of transmitters' knowledge resources, receivers seek for in-depth exchange with transmitters to acquire valuable knowledge. Then, the receivers digest and absorb the acquired knowledge, internalize it into their own knowledge, and transform themselves into knowledge transmitters, aiming to spread the acquired knowledge to other subjects. In addition, the CPDS is a virtual organization involving multiple units and subjects. In the system, the CPD activities are mainly implemented by virtual teams that closely collaborate with each other. Thus, knowledge exchanges also take place between subjects belonging to different teams, that is, knowledge diffusion occurs both inside the teams 266 Advances in Production Engineering & Management 12(3) 2017 Simulation of collaborative product development knowledge diffusion using a new cellular automata approach and between the teams. In this way, the CPD knowledge is eventually diffused and shared across the CPDS. 3. Construction of CPD knowledge diffusion model 3.1 Cellular automata Cellular automata (CA) is a network dynamics model discrete in time and space. The CA is composed of a finite number of locally interacting cells. At a certain moment, the state of a cell only depends on its own state and the state of neighborhood cells. As time goes, the simple local rule between the cells can evolve into the complex global behavior of the macro system [12-14]. The "evolution from simple local rule to complex global behavior" is one of the unique strengths of the CA model. Once it is applied to knowledge diffusion, the model will be able to depict the phenomenon of knowledge diffusion in real system from the microscopic angle: simulate the local knowledge exchanges between subjects with simple rules and evolve into the macroscopic results of global knowledge diffusion. Through the control of the initial parameters, the model can simulate the diffusion process of different types and forms of knowledge, and explain the influence of factors like organizational characteristics and knowledge subject features in the knowledge diffusion process. Therefore, the CA model is an ideal choice for CPD knowledge diffusion simulation. The CA can be expressed by a four-tuple: where C is the cell space; Q is the cell state set; V is the cell neighborhood; F is the cell state transition rule. 3.2 CA model of CPD knowledge diffusion A large number of studies have shown that the spread of social phenomena is an infection process [15]. In this research, the CPDS members in possession of a specific piece of CPD knowledge are regarded as "infectors" and those who do not possess such knowledge are viewed as "susce ptibles". For a specific type of CPD knowledge, the "infectors" can "infect" the "susceptibles" with the knowledge so that the latter acquire the knowledge and the ability to "infect" others with the knowledge. In the meantime, the knowledge "infectors" may give up the knowledge because of their memory ability. There is a certain probability for the "infectors" to transform into "susceptibles" by forgetting the knowledge. The transformation is the "restoration of health". Here, an "infector" is denoted as I and a "susceptible" is denoted as S. In light of the CA model proposed above, this paper names the CPDS knowledge diffusion model as the Knowledge-SIS (K-SIS) model. According to the four elements of the four-tuple expression of the CA, the K-SIS model is constructed as below. Cell space C: Let C be a 2D cell space containing nxn cells, representing the entire CPDS. The cells in C are expressed as c(i,j), representing the CPD teams in the CPDS. Hence, can be expressed as: As discussed before, the CPD are mainly implemented by virtual teams in the CPDS, and knowledge exchanges occur between different subjects and collaborative teams. Hence, this paper sets each cell as a CPDS collaborative team, each containing a certain number of knowledge subjects. Cell state set Q: By the above definition, each cell represents a collaborative team containing a certain number of knowledge subjects. Thus, the cell state can be expressed by the proportions of knowledge infectors and susceptibles in the cell. Let Sç^^ be the proportion of knowledge CA = (C,Q,V,F) (1) C = {c(i,j)\1