Lawrence D. Fredendall

An overview of recent literature on spare parts inventories

Abstract Spare parts inventories are not intermediate or final products to be sold to a customer, and the policies that govern spare parts inventories are different from those which govern WIP and other inventories. This paper is an update of the discussion of maintenance inventories and a discussion of the future research needed. After a discussion of unique aspects of spare parts inventories, literature is reviewed which relates to management issues, age-based replacement, multi-echelon problems, problems involving obsolescence, repairable spare parts, and special applications.

Evaluating the Deming Management Model of Total Quality in Services

This article uses the Deming management model developed by Anderson et al. (1994b) as an initial template to analyze total quality in services. While the literatures addressing quality management have developed separately for products and services, the founders of total quality portrayed this management philosophy as universally oriented. Our study first replicates two earlier studies that tested the Deming management model in manufacturing industries. Using hospitals as our unit of analysis, we realized findings similar to the earlier manufacturing studies. Next, we used contributions from the MBNQA literature to test an enhanced model. Our subsequent findings support the MBNQA concept that “leadership drives the system that creates results” and provides evidence of the ubiquitous importance of leadership for ensuring the success of a quality improvement program. Finally, an anomaly of this study and those published earlier is the inability to find support for the relationship between continuous improvement and customer satisfaction. Integrating the substantial work in the service quality literature focused on customer satisfaction measurement is recommended to future researchers to help resolve this issue and further enhance the model.

Concerning the theory of workload control

An existing taxonomy of workload control rules is adapted to classify 25 workload control rules and their components examined in prior research to create a basis to model how three workload control rule components - order selection, work aggregation and buffer limits - affect shop performance in environments that differ in their bottleneck utilization and protective capacity levels. Two of the most frequently studied rules in the literature - CONWIP and DBR - were included in the simulation. Data analysis found that the workload control rules had a significant positive effect on the shop performance measures only in environments with the highest bottleneck utilization and the lowest protective capacity. However, the work aggregation method was found to be an important component of the workload control rule. Suggestions were made for future research that could increase our understanding of workload control rules and integrate this research with our understanding of lean production.

The impact of management accounting, product structure, product mix algorithm, and planning horizon on manufacturing performance

Abstract This paper examines how three types of management accounting systems and two methods to determine product mix interact in both the short term and the long term to affect the manufacturing performance of two shops – one with a flat and the other with a deep product structure – in a highly automated industry that has a significantly high overhead content. Through a large-scale computer simulation, this study provides additional insights into the product mix decision through considering fluctuations caused by environmental uncertainty, using an integrated information system that integrates a manufacturing system and a management accounting system, considering the decision-outcome dynamic over time, the choice of cost content, and using both financial and non-financial performance measures. This study found that no single shop setting is best for all performance measures. The manager must determine which performance measures are the most important to their competitive success when making a decision about selecting or changing a management accounting system, product mix algorithm, or product structure.

The Effects of Transformational and Transactional Leadership on Quality Improvement

This article furthers the integration of leadership theory with quality management theory by testing the influence of both transformational and transactional leadership on a firms quality improvement. A survey of quality managers in the United States was conducted to measure the leadership characteristics of the firm and the firms quality improvement. This article examines the relationship of infrastructure and core quality management practices to the levels of transformational and transactional leadership in the firm. The authors found that transformational leadership significantly affects both infrastructure and core quality management practices, while transactional leadership does not significantly affect either set of practices. However, there were significantly higher levels of both transformational and transactional leadership behavior exhibited in the successful firms compared to the unsuccessful firms. The implications of these finding for quality management theory are discussed.

Load smoothing by the planning and order review/release systems: A simulation experiment

Abstract Most research studies investigating the impact of Order Review/Release (ORR) mechanisms on shop performance have focused strictly on managing the flow of orders to the shop floor once they have been generated by the planning system. This approach ignores the possibility that the manufacturing planning system may be managing the incoming work flow so that peaks and valleys in the work load have been smoothed out. This study shows, via a simple computer simulation of a random job shop, that such smoothing by the planning system can improve system performance and enhance the effects of Order Review/Release. The two ‘filtering’ mechanisms of planning system smoothing and Order Review/Release have a complementary impact on the system, with smoothing working to reduce flow time and flow time variability and ORR working to reduce work in process and work in process variability. The combination of smoothing with ORR results in shorter and more consistent lead times, lower and more stable work-in-process levels and better delivery performance. This results in a system which is very stable and predictable. Further, the study shows that the combined effects of smoothing and ORR can improve the performance of simple shop floor dispatching rules like first come-first served to the point where they are competitive with more sophisticated, due date oriented rules. This raises the possibility of simplifying control mechanisms on the shop floor by doing a better job of work load planning and order release.

Leadership and quality management practices in Thailand

Purpose – This study aims to examine the effects of leadership behaviors on quality management (QM) practices and their effects on quality performance of manufacturing companies in Thailand. The hypotheses were that leadership leads to infrastructure practices, which in turn support quality practices. These quality practices improve quality performance. This was tested using a structural equation model. In general, the model was supported although all of the individual practices examined here were not statistically significant.Design/methodology/approach – A survey of quality managers of firms located within Thailand was conducted and analyzed using structural equation modeling (SEM) to determine how leadership affected quality practices which in turn affected quality performance. The interactions of leadership with infrastructure and core variables were tested and found to be insignificant.Findings – The SEM established that leadership behaviors supported one infrastructure practice – human resource mana...

Barriers to Swift, Even Flow in the Internal Supply Chain of Perioperative Surgical Services Department: A Case Study*

This research analyzes the internal service supply chain of a perioperative surgical services department of a nonacademic community hospital using the theory of swift and even flow as a theoretical lens. Performance data were gathered using an in-depth case study and it was determined that the swift and even flow constructs did affect flow speed and variance, but did not account for all the effects observed. To understand the need for departments to coordinate their efforts with each other and how this affected flow, further analysis was conducted using insights from Pagells (2004) theory of internal integration and Gittells (2002) research about coordinating mechanisms. The findings suggest the need to incorporate a variable measuring supply chain coordination into the theory of swift and even flow.

The stochastic single machine scheduling problem with earliness and tardiness costs

Abstract This paper studies the static single machine scheduling problem with earliness and tardiness costs where job processing times are random variables and due dates are distinct and deterministic. The objective is to identify an optimal sequence which minimizes the total expeted earliness plus tardiness cost. A case where processing times are normally distributed is fully explored. We demonstrate that variations in processing times increase cost and affect sequencing decisions. Three heuristics for finding an optimal sequence are proposed. The illustrative example and computational results indicate that optimal sequences and their expected costs are significantly different from those provided by the classical deterministic single machine models. Furthermore, our computational experiments show that two of the proposed heuristics perform well in identifying optimal sequences.

Perioperative Workflow: Barriers to Efficiency, Risks, and Satisfaction

An in-depth, interdisciplinary case study was conducted to map and describe the information, material, and functional processes common to high-volume surgical specialty procedures at a southeastern US hospital. Researchers identified process defects and their effects using both observation and staff member interviews. Outdated information and structural barriers to communications were responsible for many procedural delays, procedural interruptions, and staff member work-arounds. Opportunities for improvement are identified, including redesigns and enhancement of information technology systems.