James F. CoxUniversity of Georgia | UGA · retired
James F. Cox
PhD Engineering Management
About
116
Publications
29,901
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2,297
Citations
Citations since 2017
Introduction
I am a retired professor of operations management from Terry College, UGA. I have been involved in the Theory of Constraints philosophy since 1983. My interests today are in improveing healthcare & get academics interested in TOC. It has been applied to manufacturing, supply chain, services, project management, performance measurement, strategy & tactics, lean & six sigma, etc. Goldratt's thinking processes (TP) can be used to address any problem even to teach young kids how to think.
Skills and Expertise
Additional affiliations
August 2003 - present
Independent Researcher
Position
- Professor Emeritus
June 1983 - August 2003
June 1975 - June 1983
Publications
Publications (116)
Lack of timeliness and capacity are seen as fundamental problems that jeopardise healthcare delivery systems everywhere. Many believe the shortage of medical providers is causing this timeliness problem. This action research presents how one doctor implemented the theory of constraints (TOC) to improve the throughput (quantity of patients treated)...
Despite ever-increasing resources devoted to healthcare, lack of capacity and timeliness are still chronic problems worldwide. This systematic review aims to present an overview of the Theory of Constraints (TOC) implementations in healthcare services and their outcomes. We analysed 42 TOC implementations (15 full-text articles, 12 video proceeding...
The emergency department (ED) crowding is a critical healthcare issue worldwide that leads to long waits and poorer healthcare outcomes. Goldratt’s theory of constraints (TOC) has been used effectively to improve such problematic environments for more than three decades. While most TOC solutions are simple, with many viewing them as purely common s...
ABSTRACT
Healthcare is in crisis with increasing patients’ needs, rising medical technology investment, increasing expenses, and patients’ inability to pay. To address this crisis, a new, simple, effective, and holistic management methodology is needed to rapidly and economically
improve each link’s performance in the healthcare supply chain (HCSC)...
Many primary care clinics suffer from chaos. In scheduling, providers are continually trying unsuccessfully to balance supply and demand, and in execution, to manage disruptions to provider focus and patient flow. In this research the theory of constraints’ (TOC) three processes of ongoing improvement (POOGI) provide a direction for the solution to...
Some problems are never solved and only worsen over time no matter the efforts expended. For example, look at the high and increasing costs of healthcare, government, and education and simultaneously the poor services provided. Researchers use different terms to describe these problems thought to be quite difficult or impossible to structure and so...
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 l...
A wise person learns from others mistakes. Mistakes are common even though most are preventable! Serious mistakes occur in business, government, and even in personal lives. Frequently mistakes are caused by not recognizing the situation, environment or system (referred to as system hereafter). The tendency is to hide or dismiss mistakes. That in it...
In this paper, we consider unpaced synchronous transfer lines producing a single product. The transfer line stations are arranged in a series configuration, have no buffers, and are subject to operation-dependent failures. Throughput is an important performance measure for transfer lines, and we have adopted that measure. Analytical methods for det...
The purposes of this paper are, first, to introduce several concepts and definitions related to Theory of Constraints design and management of unbalanced lines and, second, to illustrate the concepts of productive and protective capacity and inventory in a constrained line. Drum-buffer-rope is the Theory-of-Constraints based scheduling mechanism us...
While the effect of protective inventory on the performance of simple lines has received considerable attention, the same cannot be said for re-entrant lines. This paper attempts to meet that deficiency. This paper examines two different but related issues. First, the theory of constraints (TOC) evaporating cloud method is employed to show the trad...
Managing projects is a difficult undertaking–a large number of projects fail to be completed on time, on budget, or to specifications. In traditional project management literature, researchers criticise project manager skills and leadership, user involvement, top management commitment, organisation, etc. More recently, research has identified under...
This paper documents an investigation of drum-buffer-rope (DBR) scheduling and flow control methodology in single-product serial production lines. In particular, DBR flow control is reviewed and the importance of correctly representing this type of flow control mechanism in serial lines is discussed. Departures from valid DBR conceptual and simulat...
During the 19805 much attention, both pro and con, was directed toward optimized production technology (OPT). Criticism was directed at the proprietary nature of the scheduling algorithms within the software. Despite these criticisms, many large companies installed OPT. Little has been written on how the software is constructed and operates. This a...
The classical analysis of the economic order quantity (EOQ) problem ignores the effect of inflation. When a firm's cost factors are expected to rise at an annual rate of 10 percent or more, what adjustments in order quantities should the firm make to control its lot-size inventory (or cycle stock)? Using a model that includes both inflationary tren...
Material requirements planning (MRP), a comprehensive planning and control technique based upon the dependent demand principle, enables manufacturing organizations to provide better customer service, reduce inventory investment, and increase resource utilization. This paper extends the dependent demand principle to the service sector and thus provi...
Supply chain management is a topic that many practitioners and students generally find difficult to understand (Boudette, 2005). The authors present a supply chain game that they have found to be an effective tool to increase student interest in and comprehension of supply chain management. The supply chain game literature is briefly reviewed. The...
Standard OR/MS methods mainly focus on ‘hard’ aspects of problems represented by quantitative or mathematical formulations. Organisational settings typically pose challenges in the use of such methods, in that they may be inadequate to capture the ‘softer’ issues surrounding human behaviours, organisational practices and policies. Over the last 20...
Purpose - Problem-solving techniques for poorly structured problems have been the subject of recent academic research and popular press texts. The purpose of this paper is to explain the use of one of the Theory of Constraints thinking process (TP) tools — the Current Reality Tree (CRT). The purpose of the tool is to clearly identify the root probl...
Production planning and control (PPC) systems and operations performance measures are topics that students generally find both boring and difficult to understand. In the article, the authors present a production line game that they have found to be an effective tool to increase student interest in the topics as well as student comprehension. The ga...
This paper provides a constructive illustration of ongoing methodological developments in the use of TOC Thinking Processes and logic tools. In particular, the paper outlines a new approach to using the Evaporating Cloud, Current Reality Branch and Future Reality Branch, and demonstrates how that approach can be used to construct a comprehensive pr...
Although this application of the Thinking Process of the Theory of Constraints has been applied to a forestry supply chain, the Thinking Process can be applied to analyze and solve most problems. Two Thinking Process tools, the Current Reality Tree and the Future Reality Tree, are described and illustrated. The Thinking Process methodology is actio...
Prior work using the classificatory frameworks of Mingers, Mingers and Brocklesby has proven useful in understanding the complementary nature and characteristics of traditional Operational Research/Management Science (OR/MS), Theory of Constraints (TOC) and systems methodologies, by examining the philosophical assumptions that underpin them. This p...
The semiconductor wafer fabrication manufacturing environment is one of the most difficult in which to plan and control. Long and re-entrant routings and high yield loss on new products are two characteristics that impact system performance. This research provides an exploratory investigation of two simplified flow control mechanisms to determine i...
Flow control mechanisms have been a topic of academic research for several years. With the growth of business-wide information systems such as enterprise resource planning and supply chain, better planning, scheduling and control of the business transformation process is required in order to achieve increased throughput, reduced inventories, shorte...
Since its inception, cost accounting has provided data to managers for the development of internal organizational performance measures. In the mid 1980s, Dr Eli Goldratt introduced a new management philosophy called the theory of constraints (TOC). This philosophy contained a new set of performance measures which linked together the strategic objec...
The purposes of this paper are, first, to introduce several concepts and definitions related to Theory of Constraints design and management of unbalanced lines and, second, to illustrate the concepts of productive and protective capacity and inventory in a constrained line. Drum-buffer-rope is the Theory-of-Constraints based scheduling mechanism us...
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 inf...
Examines the issue of transfer pricing and the effects on business enterprises. What is transfer pricing; Details on the neoclassical economics view; Factors which contribute to pricing problems; Details on traditional cost management profit margins.
International competition has changed the nature of the US manufacturing environment. Manufacturing firms must now strategically examine customers’ needs in all served market segments for competitive survival. Moreover, firms must determine those products or service attributes which are ‘order qualifiers’ — necessary for either getting into or stay...
This paper discusses the findings of a study of production planning and control systems in nine repetitive manufacturers in the southeast United States. The purpose of the study was to identify the methods used by repetitive manufacturers to plan and control production. The companies in the study were selected so that three companies were noted for...
Throughout the 1980s and still up to today interest and confusion exists over the use of theory of constraints (TOC) and the software package called OPT. The first area of confusion is the question of the differences between OPT and TOC. Are they one and the same or does TOC replace OPT? Most articles concerning these methods use the term OPT, whil...
Researchers in management and marketing theory have long postulated a role between and management strategies used for the production process and for the products. Hayes and Wheelright (1979a) developed the product-process matrix to describe the relationship and in a following article (1979b) they identified strategic consequences implied by the mat...
Master production scheduling (MPS) in a theory of constraints (TOC) environment requires a different focus and understanding than under material requirements planning systems. Misunderstanding of the concepts or the belief that there is no need to change the MPS function may lead to serious problems and cause the system to fail to achieve all of th...
Organisational coordination on the firm's strategic objectives is essential to compete effectively in the global economy. A systematic approach is needed to synchronize the firm's activities in relation to its objectives. Integrated performance measurement systems provide a vehicle for improved organisational coordination. The purpose of this explo...
This article presents an analysis describing how the selection of proper competitive factors and modification to a firm's performance measurement system provide the means to control, coordinate and communicate product flow, from order receipt to customer shipment, through the production process. The article also discusses how modifications to the t...
This paper discusses the applicability of the Theory of Constraints (TOC) in the process flow industry and compares TOC to the current practice. The Drum-Buffer-Rope methodology is altered to meet the needs of the process flow environment. Guidelines for the strategic location of and determination of the reduced WIP inventory levels are provided.
The article discusses the negative effect of management decisions regarding transfer price. The author remarks that, many companies are infusing market pressure into the establishment of the transfer price by allowing organizations to evaluate the decision of using/supplying internally versus using/supplying externally. Using external sources requi...
In today's economy, the importance of and emphasis on customer service has been steadily increasing. In response to this shift, the field of operations management has expanded both its teaching and research horizons to include not only the traditional concepts of production but also those of service operations. Companies are becoming increasingly a...
This article discusses the results of an empirical study conducted to examine the relationships between production planning and control using Just-in-Time methods, and customer order management in repetitive manufacturing.
This paper examines the forecasting function supporting large-scale inventory systems in leading firms. Little research has been conducted on managing the forecasting function when hundreds and, in some cases, tens of thousands of items are managed. Case studies are used to explore how companies noted for having state-of-the-art inventory systems h...
V-A-T analysis is a procedure which categorizes manufacturing operations based upon the nature of product flow via the structure of the routeings and bill of materials. The letters V, A, and T stand for the shape of the dominant product routeings and bill of material structures within a manufacturing facility. The purpose of this article is to exam...
The article discusses the benefits derived by implementing just-in-time (JIT) systems in a manufacturing process. According to the author, the just-in-time philosophy is clearly not a fad; it is good management and an effective method of improving the manufacturing processes. JIT works because its elements are designed to continuously identify and...
Results of a study conducted to understand how performance is evaluated in just-in-time (JIT) operations are reported in this paper. The purpose of the study was to develop a series of propositions concerning the performance criteria, standards, measurement techniques, and reporting methods that are appropriate in JIT environments. Ten propositions...
Computer integrated manufacturing (CIM) is a concept that combines various technologies to produce an entire integrated factory. Usually CIM consists of such technologies as computer aided design and computer aided manufacturing (CAD/CAM), robotics, automated material handling and identification, machine vision, and a communications network that li...
The historical use of performance measures and the problems associated with productivity improvement in industry today are reviewed. A simple numerical example illustrates the problems arising when each functional area uses its own performance standard. A short case study highlights the problems of an actual company's performance measurement system...
The article discusses the strategic use of work-in-progress (WIP) inventory in stores and buffer inventories using two classification schemes, bill-of-material shape and plant type. The first important classification is the shape of the bill of material. Several bill-of-material structures exist. The manufacturing bill, the bill of material for an...
This paper reports the results of a survey of early implementators of the just-in-time (JIT) philosophy in the United States with particular emphasis on the identification of implementation problems and operating problems. There were 39 respondents to the survey who were in the process of implementing JIT. Five classes of implementation problems an...
This research describes how five production planning and control functions are accomplished by successful information systems in process industries, identifies factors that influence the design of the systems that support these functions, and models the relationships between influential factors and planning and control systems. A case study methodo...
The article presents information on the findings of a study on the use of operations research (OR) techniques in industrial management in the U.S., the relative utilization of several OR techniques, and the use of specific OR techniques in 11 areas of production management. The results from the study indicate a high degree of consistent use for the...
We present the results of a 1985 study, which replicates a 1975 study by Cox, Ledbetter, and Smith (1977), and attempt to mea sure the use of simulation modeling to support decision-making in major U.S corporations. Specifically, the purposes of the paper are to (1) measure the development and use of simulation models at all levels of decision-maki...
Discriminant analysis was used to develop a profile of a typical Quality Circle Programme participant. Selected demographic, attitudinal, and behavioural characteristics were evaluated. Six characteristics significantly differentiated quality circle members from non-members, including educational level, tenure, job satisfaction, consideration, perf...
The primary finding of this survey is that both the microcomputer and minicomputer material requirements planning (MRP) software package markets have changed significantly over the past three years. Not only are more packages available, but they support more production, marketing, accounting, and financial functions. Some of the microcomputer packa...
An analysis of how directors of the MS/OR function in industry view the industrial-academic interfaces of (1) professional journals, (2) professional societies, and (3) the directors' hiring practices replicates a study by Cox, Ledbetter and Smith left bracket 1978 right bracket , allowing comparison to be made and changing views to be identified....
Two separate approaches are dominant in the systems analysis and design literature: the structured approaches and the prototyping approach. Much has been written about the advantages and disadvantages of each of these methodologies. No specific guidelines, however, have been developed to assist in choosing which approach might be most appropriate....
Productivity increases attributed to the Japanese management approach known as just-in-time (JIT) include better customer service, higher quality levels, increased labour and machine efficiency and reduced inventory levels. These potential benefits, as well as others, have caused many large companies to examine JIT. Most of this interest has been f...
The article presents information on the selection of material requirement planning (MRP) software for small businesses. The emergence of microcomputers has led to automation of many tasks which small businesses performed manually until recently. One strong indicator of this is the number of software packages becoming available for inventory applica...
The article presents information on material requirements planning (MRP) design and implementation issues for small manufacturers. MRP is an inventory and production planning system, created for an environment in which batches of finished goods are made from a large number of components. In order to implement MRP a firm must have correct bills of m...
Thin paper presents a multiple criteria model for combining quantitative and qualitative approaches to plant layout. The quantitative factor (work flow) is weighted by the qualitative factor (closeness rating) to form the model. The objective is to minimize the total weighted work flow volume between departments. An heuristic approach is used on an...
Numerous firms experience rapid changes in information needs in today’s dynamic business environments. Many of the traditional systems development life-cycle (sdlc) approaches to systems design do not provide for incorporating changes to proposed designs during development of the information system. The sequential approach taken with these traditio...
Many approaches have been proposed for systems analysis but few researchers propose a continuous educational exchange between users and systems analysts. This type of exchange is critical to successful system implementation when the environment is complex and subject to change. Both users and systems analysts must be informed of the others' roles a...
This paper presents Manufacturing Resource Planning, an information system that will enable the developing and monitoring of strategic plans. Incorporation proven material and capacity requirements planning techniques, strategic planners can determine readily the impact of their plans on the manufacturing resources of the company. Decision making i...
The attitudes of employees toward any new system implementation are a critical factor in the system's success. Prior to implementing an office automation system, a study was performed in a large department comprised of ten offices in one large firm. Attitudes of employees toward office automation were assessed, as well as their level of understandi...
This controlled study was done to quantify the effects of inventory control accuracy attributable to cycle counting. It answered the following questions: Are estimates of actual inventory on hand more accurate with cycle counting that with periodic inventorying? Is the range of differences between actual shelf quantities and recorded inventory quan...
Since office automation usually involves much interaction among employees in the work environment, a particular analysis and design problem that must be faced in many office environments is the decision on the degree communication networking of personnel and work centers. This article presents a technique that can be used to assist in determining t...
Manufacturing information systems are among the most complex to design, implement, and maintain. Few systems are completely successful. This paper provides the framework of one of the most popular manufacturing information systems, a manufacturing resource planning system, discusses the potential benefits of a successful system, and describes the p...
The economic order quantity concept has received much attention. However, the model is severely restricted by the assumption of constant demand. This study presents a procedure for adjusting the economic order quantity model for the cases of increasing or decreasing linear trend demand patterns. The primary advantage of the proposed method is its s...
Several lot sizing procedures for determining order points and order quantities have received attention in the literature. A few of these are as follows: Economic Order Quantity, Least Total Cost, Periodic Order Quantity, Lot for Lot, Part-Period Balancing, Silver-Meal algorithm, and the Wagner-Whitin algorithm. While some of the above procedures a...
THE PURPOSE OF THIS WORK IS TO PRESENT AN AUDITING INSTRUMENT DESIGNED TO ASSIST IN THE IDENTIFICATION OF POTENTIAL ANDEXISTING PROBLEMS WITH MRP SYSTEMS. ALTHOUGH THE INSTRUMENTIS DESIGNED FOR MRP SYSTEMS IN GENERAL, IT SHOULD ENABLE MOST MANUFACTURING FIRMS TO IDENTIFY PROBLEMS WITH THEIR PARTICULAR MRP SYSTEM. ESTABLISHING AND USING AN AUDITING...
The criteria traditionally used to classify organizations as manufacturing and service offer little utility to managers in planning and controlling operations. The identification of similarities that allow implementation of proven management techniques is critically important regardless of organizational classification. This paper briefly reviews c...
Focuses on an auditing instrument designed for evaluation of material requirements planning (MRP) system to assist in the identification of potential and existing problems within the system. Identification of technical, management and employee attitude problems using questionnaires in the auditing instrument; Need for a thorough knowledge of produc...
Questions
Question (1)
Goldratt's thinking processes have been used extensively in various industries globally to identify core problems, develop win-win solutions and structure implementation plans that reduce resistance. In business research, high powered statistical techniques and operations research techniques are required for publishing in quality academic journals. In the hard sciences logic and gedanken exercises are frequently used to prove hypotheses. Are there references for using logic in academic soft science research? Are there other accepted forms of applied logic in the academic literature?
Projects
Projects (3)
I have found little "how to" research on design science. It seems to be a general concept with little directions on how to do from a specific case or cases to mid-range theory. I am quite proficient at Goldratt's theory of constraints thinking process (TP) which are used frequently with great success to identify and address the core problems in any organization. I am trying to provide the missing links in how to use the TP to solidify case study research (qualitative research) increasing its rigor. I feel this is a major opportunity to evaporate the rigor versus relevance dilemma in academic research.