Lynn Boyd

Theory of constraints: a theory for operations management

Purpose – The purpose of this paper is to suggest that the theory of constraints (TOC) can serve as a general theory in operations management. The paper first investigate linkages between TOC and the core concepts/components of operations management (OM) and show how OM concepts can be integrated with TOC using examples from the published TOC literature. A second important purpose is to show that TOC, as a theory, has properties essential for a good theory.Design/methodology/approach – Using a commonly accepted categorization of operations decisions (process, quality, inventory and capacity), traditional views, and approaches to operations decisions to those inherent in the TOC are compared.Findings – The paper concludes that the TOC provides approaches to operations decisions that avoid pitfalls of local optimization by reaching across functional boundaries in organizations. In addition, while the TOC appears to meet the criteria of a good theory, it has not been empirically tested for the most part.Orig...

Constraints management: What is the theory?

A number of attempts have been made to develop theories in operations management (OM) (e.g. trade‐off theory by Skinner, customer‐contact model by Chase and Tansik, product‐process matrix by Hayes and Wheelwright). Researchers in OM acknowledge that there is no widely‐accepted theory on which OM rests or which serves as a unified OM theory to integrate existing theory‐like principles or informal theories. Constraints management (CM) has been developed over the past 20 years by consultants and practitioners but has received little attention from OM researchers. The authors believe that constraints management may serve as a broad theory within operations that will allow integration of a great deal of existing OM research. The main objectives of this paper are to propose a construct, throughput orientation, discuss its core dimensions, and develop a theoretical model of CM. The paper also suggests several hypotheses that might be empirically tested to establish CM as a recognized theory in the field of operations management. The paper concludes with suggestions for future research.

Optimal decision making using cost accounting information

The primary objective of this paper was to compare the results of using four different cost accounting systems (traditional cost accounting, activity-based costing, direct costing, and throughput accounting) in a resource-constrained production environment in order to make two categories of decisions that managers frequently use cost accounting information to make. The research design includes a survey of manufacturing managers to determine what decisions cost accounting information is used to make, and a simulation model to determine the results of the decisions. In addition, the results of the four cost accounting models are compared with a linear programming solution. The study found that the through-put accounting model in all cases made the same decision as the linear programming model, but the other three cost accounting systems generally produced suboptimal results. Our conclusion is that for a cost accounting system to provide information for optimal decisions, it must (1) be aware of production constraints, and (2) not use allocated costs.

A New Approach to Strategy Formulation: Opening the Black Box.

Abstract The strategic planning process is arguably one of the most important topics taught in a management class. Moreover, the subtopic of strategy formulation is both the most pivotal and the most difficult to teach. As many theorists argue, strategy formulation is the “black box” of strategic planning. One approach for both clarifying and teaching strategy formulation uses the thinking process tools of the theory of constraints. In this article, we briefly describe these thinking process tools and apply them to a popular introductory strategy case to illustrate how they can be used to teach strategy formulation. Implications of the thinking process for other strategic management issues are also discussed.

The evaporating cloud: a tool for resolving workplace conflict

Purpose – This article has two purposes. The first is to synthesize the important current concepts, definitions, and styles of resolving and/or managing workplace conflicts. The second is to introduce a systematic approach to resolving workplace conflicts.Design/methodology/approach – Historical approaches to conflict management are briefly reviewed and Goldratts evaporating cloud is introduced as a structured approach to achieving win‐win solutions to workplace conflicts. A comprehensive case is used to demonstrate the application of the suggested approach.Findings – Goldratts evaporating cloud provides a systematic approach to identifying the conflicting needs or interests of the parties to a conflict, and a process for making explicit the assumptions underlying the conflict and challenging their validity, leading to win‐win solutions to workplace conflicts. The evaporating cloud incorporates well‐accepted principles of achieving win‐win solutions and complements existing approaches.Research limitatio...

An Excel‐based dice game: an integrative learning activity in operations management

Purpose – The purpose of this paper is to extend the role of the theory of constraints (TOC) to complement, reinforce, and help integrate conventional operations management (OM) concepts by using an Excel‐based version of the dice game discussed in The Goal by Goldratt.Design/methodology/approach – The paper discusses the motivation for and the development and evaluation of an Excel‐based dice game model of a production system for novice managers to experiment with. A set of experiments related to OM concepts (e.g. inventory, capacity, and variability) is designed and counterintuitive results are discussed. The paper concludes by demonstrating how TOC provides an integrative OM framework.Findings – The novel The Goal by Goldratt serves as a comprehensive case study in OM. The computerized dice game provides a mechanism for understanding relationships among various OM concepts. The proposed set of experiments strengthens the linkages between OM and TOC concepts. Managers can conduct additional experiments ...

The International Journal of Production Research at 55: a content-driven review and analysis

The articles published in the International Journal of Production Research (IJPR) since inception have made a significant contribution to operations management (OM) research, firmly establishing IJPR as one of the most important outlets for OM research. This paper uses a text mining technique called Latent Semantic Analysis to identify the core areas of research published in IJPR since inception, and reveals how the focus on topics has evolved over time. The data consist of the abstracts of all articles published in IJPR from the inception of the journal through December 2015. The study identifies 16 core areas of research and provides a detailed analysis of how these core areas have evolved over time. The results from this data-driven analysis of 55 years of research in IJPR not only provide a comprehensive examination of past research in the journal but also important insights into the evolution of key areas of research in operations management.

Experiential exercises with four production planning and control systems

In the authors’ experience, students have difficulty in understanding the differences between production planning and control techniques. Presumably, current business managers, although they have heard about these systems, may also lack clarity on the differences between them. We outline manual games for simulating production runs in four systems (Materials Requirements Planning, Just-In-Time, Theory of Constraints and CONWIP) to give managers and students’ insight into the mechanics of different production planning control techniques. We then provide excel-based simulation tools to allow users to vary parameters for each system and see the impact on inventory and throughput. We believe that the combination of manual and excel-based games significantly enhances understanding of the systems as well as their differences.

An analysis of research methods in IJPR since inception

Production research as an academic field has experienced tremendous growth in the last few decades. The progress in production research and operations management (OM) research is due in no small part to the increasing sophistication and availability of research methods in this field. This paper explores the role of research methods in OM publications through an analysis of the entire corpus of research as represented in a leading OM journal, the International Journal of Production Research (IJPR). This paper reports on a study of all 8653 academic article abstracts published in IJPR since inception to identify the research methods used to both generate and analyse data over the 55 years from the journal’s inception in 1961 through 2015. The study classifies articles using a 6 × 6 typology on the dimensions of data generation and data analysis and provides a summary of the use of research methods and the evolution of their use over time. For example, mathematical modelling has become the dominant method for data generation while experiments have become less popular. Though meta-heuristics and optimisation remain the most popular methods for data analysis, data mining methods have gained pained popularity, comparable to statistical methods.

Using the theory of constraints’ processes of ongoing improvement to address the provider appointment scheduling system design problem

Abstract Health care is in crisis today: costs are rising, demand exceeds supply, quality is questioned and patient wait times are excessive while providers and staff are simultaneously overworked and frustrated. No one has a comprehensive system solution to providing more, cheaper, better, and faster health care, even in primary care practices, the first link in the health care supply chain. Additionally, this link like others frequently experiences the combination of complexity, uncertainty, and local optimisation simultaneously to create a chaotic environment. Health care problems have been called ill-structured (also “wicked”) and because of their tangled web of stakeholders with different and conflicting objectives defy traditional optimisation research methodologies. Proper design and management of the provider appointment scheduling system (PASS) provides a direction for a win–win health care solution (more, cheaper, better, and faster). Our objective is to provide a generic strawman process for developing a robust PASS for most environments. A theory of constraints thinking processes (TP) analysis was conducted on the academic research using a primary care practice to validate both entity and causality existence. From this integrated analysis, a robust process for designing a PASS resulted. Last, we show that Goldratt’s TP provides a logical, rigorous framework for qualitative research and design science.