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Modeling the Effect of Product Architecture on Mass-Collaborative Processes

Traditional product development efforts are primarily based on well-structured and hierarchical product development processes. The products are systematically decomposed into subsystems that are designed by dedicated teams with well-defined information flows. Over the last 2 decades, a new product development approach called mass-collaborative product development (MCPD) has emerged. The fundamental difference between a traditional product development process and a MCPD process is that the former is based on top-down decomposition while the latter is based on evolution and self-organization. The paradigm of MCPD has resulted in highly successful products such as Wikipedia, Linux, and Apache. Despite the success of various projects using MCPD, it is not well understood how the product architecture affects the evolution of products developed using such processes. Toward addressing this gap, we present an agent-based model to study the effect of product architectures in MCPD processes. The model is executed for different architectures ranging from slot architecture to bus architecture and the rates of product evolution are determined. The agent-based modeling approach allows us to study how (a) the degree of modularity of products and (b) the sequence of decoupling affect the evolution time of individual modules and overall products developed through MCPD processes. The approach is presented using the architecture of mobile phones as an illustrative example. This approach provides a simple and intuitive way to study the effects of product architecture on the MCPD processed. It is helpful in determining suitable strategies for product decomposition and module decoupling, and in identifying the product architectures that are suitable for MCPD processes.

Modeling the Effect of Product Architecture on Mass Collaborative Processes: An Agent-Based Approach

Traditional product development efforts are based on well-structured and hierarchical product development teams. The products are systematically decomposed into subsystems that are designed by dedicated teams with well-defined information flows. Recently, a new product development approach called Mass Collaborative Product Development (MCPD) has emerged. The fundamental difference between a traditional product development process and a MCPD process is that the former is based on top-down decomposition while the latter is based on evolution and self-organization. The paradigm of MCPD has resulted in highly successful products such as Wikipedia, Linux and Apache. Despite the success of various projects using MCPD, it is not well understood how the product architecture affects the evolution of products developed using such processes. To address this gap, an agent-based model to study MCPD processes is presented in this paper. Through this model, the effect of product architectures on the product evolution is studied. The model is executed for different architectures ranging from slot architecture to bus architecture and the rates of product evolution are determined. The simulation-based approach allows us to study how the degree of modularity of products affects the evolution time of products and different modules in the MCPD processes. The methodology is demonstrated using an illustrative example of mobile phones. This approach provides a simple and intuitive way to study the effects of product architecture on the MCPD processes. It is helpful in determining the best strategies for product decomposition and identifying the product architectures that are suitable for the MCPD processes.© 2009 ASME

Analysis of the interdependent co-evolution of product structures and community structures using dependency modelling techniques

Within the engineering design literature, dependency modelling techniques have been used to model the structure and evolution of products. While a products structure has significant implications on the products quality and the complexity of product development process, recent studies within organisational science suggest that an organisations structure also has a direct impact on the product structures. This interdependence is particularly important in open-source products developed by communities because there is no community structure imposed at the beginning of the process. Both the product structure and the community structure undergo dynamic co-evolution. Understanding this co-evolution is crucial as open-source development processes are being extended beyond software products to hardware products. To understand the interdependence between product and community structures, empirically testable hypotheses, based on the theory of socio-technical coordination, are formulated in this paper. A dynamic network-based approach is proposed where products are modelled as networks of interfacing modules and communities are modelled as networks of collaborating participants. The proposed approach for testing the hypotheses involves (a) modelling the evolution of networks across consecutive versions and (b) measuring the overlap between anticipated and actual communities. The approach is presented for Drupal, which is an open-source software product. Drupal is chosen due to the availability of product and community data for different versions. Based on the analysis, it is concluded that product structures significantly influence the community structures. However, the impact of community structures on the product structures is weak. While the results are specific to the case study, the approach is general enough to be utilised for other open-source software and hardware products. The approach can also be used to model the evolution of loosely coupled informal communities within traditional organisations.

USING SYSML FOR CONCEPTUAL REPRESENTATION OF AGENT-BASED MODELS

Agent-based modeling (ABM) is a technique used to simulate systems consisting of autonomous interacting entities called agents. It has shown great advantages in modeling complex systems with independent but interacting actors. ABM has been successfully applied to a variety of systems. Despite the availability of a large number of tools for ABM, there is limited support for the conceptual design of agent-based models. Further, the currently available tools capture both the model information and the tool-specific execution information in an integrated manner. This limits model reusability, which is an impediment to systematic validation of models. In this paper, we use the systems modeling language (SysML) for building conceptual models of agent-based models. We discuss how the different diagrams in the SysML language can be used to represent different aspects of agent-based models. Further, we propose an approach for automatically generating executable agent-based models from their conceptual SysML representations. The proposed approach is illustrated using a model of mass-collaborative processes as an example. The proposed approach for conceptual representation of agent-based models in SysML and automatic extraction of executable models has the potential to greatly improve reuse, reconfiguration, and validation of agent-based models.Copyright

Building Smaller Sized Surrogate Models of Complex Bipartite Networks Based on Degree Distributions

This paper presents an approach for generating surrogate bipartite networks with varying sizes based on degree distributions of given bipartite networks. The resulting surrogate networks can be used for problems such as design of algorithms for similarity search, community detection and clustering, and recommender systems. The primary advantage of using smaller surrogate networks over original large-scale networks is the reduction in associated computational expense. Degree distribution is chosen because of its widespread acceptance, simplicity, and prior literature suggesting its ability to better capture large-scale network properties. The approach is illustrated using a bipartite network from an open-source software development repository. The network consists of nodes representing people and projects, and edges representing people working on different projects. A comparison between the surrogate networks and the original networks is presented. The results show that the resized networks obtained using the proposed approach can be used to match the original degree distribution. A comparison of seven other network characteristics is also provided.

Analysis of the Structure and Evolution of an Open-Source Community

Open-source processes are based on the paradigm of self-organized communities as opposed to traditional hierarchical teams. These processes have not only been successful in the software development domain, but are increasingly being used in the development of physical products. In order to successfully adapt open-source processes to product realization there is a need to understand how open-source communities self-organize and how that impacts the development of the products. Towards the direction of fulfilling this need, we present an analysis of an existing open-source community involved in developing a web-based content-management platform, Drupal. The approach is based on the analysis of networks using techniques such as social network analysis, degree distribution, and hierarchical clustering. Openly available information on the Drupal website is utilized to perform the analysis of the community. The data is transformed into two weighted undirected networks: networks of people and networks of Drupal modules. Both the structure of these networks and their evolution during the past six years are studied. The networks are visualized by mapping them into images. Based on the analysis, it is observed that the structure of the Drupal community has the characteristics of a scale-free network, which is similar to many other complex networks in diverse domains. Finally, key trends in the evolution of the networks are identified and the possible explanations for those trends are discussed.Copyright

A Generative Network Model for Product Evolution

Modeling the structure and evolution of products is important from the standpoint of improving quality and maintainability. With the increasing popularity of open-source processes for developing both software and physical systems, there is a need to develop computational models of product evolution in such dynamic product developments scenarios. Existing studies on the evolution of products involve modeling products as networks, taking snapshots of the structure at different time steps, and comparing the structural characteristics. Such approaches are limited because they do not capture the underlying dynamics through which products evolve. In this paper, we take a step toward addressing this gap by presenting a generative network model for product evolution. The generative model is based on different mechanisms though which networks evolve—addition and removal of nodes, addition and removal of links. The model links local network observations to global network structures. It is utilized for modeling and analyzing the evolution of a software product (Drupal) and a physical product (RepRap) developed by open source processes. For the software product, the generated networks are compared with the actual product structures using various network measures including average degree, density, clustering coefficients, average shortest path, propagation cost, clustered cost, and degree distributions. For the physical product, the product evolution is analyzed in terms of the proposed mechanisms. The proposed model has three general applications: longitudinal studies of a products evolution, cross-sectional studies of evolution of different products, and predictive analyzes.

Network-Based Analysis of the Structure and Evolution of an Open Source Software Product

In this paper, an analysis of product structures in open source software (OSS) at both product level and module level is presented. At the product level, the product structures are modeled as complex networks, and the evolutionary characteristics of product structures are analyzed by using network analysis metrics. At the module level, linking mechanisms, which describe how a module is attached with other modules, are proposed. The linking mechanisms are modeled as probability functions dependent on the degrees of linking modules. A case study from an open source software project, Drupal, is presented. The evolutionary trends of Drupal product structures are analyzed and discussed. Finally, a model is presented to illustrate the effects of linking mechanisms at the module level on the product structures at the system level. The results indicate that the model built using the proposed linking mechanisms generates networks whose evolutionary characteristics are close to that of the original network.

EVALUATING SOCIO-TECHNICAL COORDINATION IN OPEN-SOURCE COMMUNITIES: A CLUSTER-BASED APPROACH

In complex product development, coordination is the act of managing dependencies between artifacts. Sociotechnical coordination is the achievement of coordination through the alignment of organizational structures and product structures. Socio-technical coordination is achieved in hierarchical product development organizations by aligning the organizational structure with the system architecture. However, within virtual community-based product development such as open source development, the organizational structure is not designed by a central authority. In contrast, the community evolves as a result of participation of individuals and their communication with other individuals working on the project. Hence, understanding and quantifying socio-technical coordination is particularly important in open-source communities. Existing approaches to measuring socio-technical coordination are based on the congruence between ideal communication and the actual communication structures within communities. The primary limitation of existing approaches is that they only account for explicit communication between individuals. Existing measures do not account for the indirect communication between individuals and the shared knowledge that individuals working on a joint project possess. Due to these limitations, the socio-technical coordination values have been observed to be very low in the existing literature. We propose two alternate approaches to measuring socio-technical coordination based on clustering techniques. We illustrate the approaches using a case study from an open source software development community. The proposed approaches present a broader and more encompassing view of coordination within open source communities.