In much of the current literature on supply chain management, supply networks are recognized as a system. In this paper, we take this observation to the next level by arguing the need to recognize supply networks as a complex adaptive system (CAS). We propose that many supply networks emerge rather than result from purposeful design by a singular entity. Most supply chain management literature emphasizes negative feedback for purposes of control; however, the emergent patterns in a supply network can much better be managed through positive feedback, which allows for autonomous action. Imposing too much control detracts from innovation and flexibility; conversely, allowing too much emergence can undermine managerial predictability and work routines. Therefore, when managing supply networks, managers must appropriately balance how much to control and how much to let emerge.

a b s t r a c tThe literature on supply chain management (SCM) has consistently promoted the "bright side" of collaborative buyer-supplier relationships (BSRs). Based on the social capital argument, SCM scholars have investigated how a buyer can gain access to and leverage resources through its collaborative BSRs. Our study extends this research stream by considering the "dark side" of social capital in BSRs. It evaluates how social capital in its cognitive, relational, and structural forms contributes to or impedes value creation within BSRs. Both primary survey measures and secondary objective measures have been used in data analysis. The results show the presence of both the bright side, confirming the existing literature, and the dark side, extending the literature. There is an inverted curvilinear relationship between social capital and performance: Either too little or too much social capital can hurt performance. This study confirms that building social capital in a collaborative BSR positively affects buyer performance, but that if taken to an extreme it can reduce the buyer's ability to be objective and make effective decisions as well as increase the supplier's opportunistic behavior. Our study also examines how a buyer can delay the emergence of the dark side. It opens up new research avenues in the collaborative BSR context and suggests directions for future research and practice.

Since the seminal article by Eisenhardt (1989), scholarly interest in case research has mushroomed in operations management and organization sciences. Volumes of methodological texts are matched with a massive amount of empirical research that seeks to apply and further develop case research as a scientific method. What is missing from this literature is a treatment of the methodological diversity of case research. In this paper, we seek to unveil this heterogeneity by describing three distinct methodological accounts of case study: theory generation, theory testing, and theory elaboration. Each approach has its own idiosyncrasies, in particular when it comes to the interplay between theory and empirics. A typical case research incorporates both existing theories and empirical data to varying degrees. In light of this heterogeneity, we re‐interpret key aspects of extant contributions and discuss guidelines for future case research. We propose that ultimately, case research rigor is determined by attention to idiosyncrasy and transparency of reasoning. We conclude by arguing that we have witnessed in the past 25 years in organization research what amounts to the Renaissance of case research.

A supply base is defined as the portion of a supply network that is actively managed by a buying company. The buying company, referred to as the focal company, manages the suppliers in the supply base through contracts and purchasing of parts, materials, and services. To facilitate better management of a supply base, we observe ''complexity'' as a key area of managerial consideration and apply the literature on complexity to the supply base. Supply base complexity is conceptualized in three dimensions: (1) the number of suppliers in the supply base, (2) the degree of differentiation among these suppliers, and (3) the level of inter-relationships among the suppliers. Four propositions have been formulated in terms of four major areas of research within supply chain managementtransaction costs, supply risk, supplier responsiveness, and supplier innovation. Corollary propositions are also stated. Although a reduction in complexity may lead to lower transaction costs and increased supplier responsiveness, in certain circumstances it may also increase supply risk and reduce supplier innovation. Therefore, reducing supply base complexity in general may be a costefficient approach, but blindly reducing it may potentially decrease the buying company's overall competitiveness. #

With an increasing trend toward using more qualitative case studies, there have been meaningful and significant contributions to the field of operations management, especially in the area of theory building. However, in many of the qualitative case studies we reviewed, sufficient details in research design, data collection, and data analysis were missing. For instance, there are studies that do not offer sampling logic or a description of the analysis through which research outcomes are drawn. Further, research protocols for doing inductive case studies are much better developed compared to the research protocols for doing deductive case studies. Consequently, there is a lack of consistency in the way the case method has been applied. As qualitative researchers, we offer suggestions on how we can improve on what we have done and elevate the level of rigor and consistency.