An Evaluation of Capacity Sensitive Order Review and Release Procedures in Job Shops

We investigate the performance of capacity-sensitive order review and release (ORR) procedures in job shop environments that have not been previously explored. Previous research has ignored the case of job shops which must perform to very tight due-dates because of time-sensitive customers. We propose and test a new capacity sensitive ORR procedure called path based bottleneck (PBB) in such environments, along with the modified infinite loading (MIL) procedure which has been shown to work well in several studies. We compare the performance of these two controlled release rules with that of immediate release rule under different conditions of capacity utilization and customer specified exogenous duedates. Our results indicate that PBB performs well in lowering total costs when due-dates are tight, while MIL is a better procedure with relatively loose to medium due-dates. We also show that in many cases, the shortest processing time (SPT) dispatching rule is a superior performer than a due-date based rule like critical ratio (CR); a conclusion which is contrary to the existing research in this area. In addition, the shop floor control policies recommended are shown to be sensitive to the cost structure of the firm. The managerial implications of this research in providing effective shop floor control in job shops operating under tight due-date conditions are also discussed.     

The Impact of Learning and Labor Attrition on Worker Flexibility in Dual Resource Constrained Job Shops

This study investigates the impact of worker learning, worker flexibility, and labor attrition on the system performance of a dual resource constrained (DRC) job-shop. The effects of learning and labor attrition have not been previously addressed in DRC literature. Results from the study, consistent with previous literature, show that the greatest benefits are achieved when inter-departmental worker flexibility is incrementally introduced into the system. In addition, the learning environment, which depends on the initial processing time of jobs and the learning rates of workers, is shown to impact the acquisition of flexibility. The study also shows that the impact of labor attrition on system performance under certain shop conditions may be significant.     

Resource Flexibility Issues in Multistage Manufacturing

We test the situational impact of two types of resource flexibility, machine flexibility and labor flexibility, in a material requirements planning (MRP)-driven production system. Machine flexibility has not been treated in prior multistage research, only labor flexibility. Machine flexibility is closely related to a plant's positioning strategy. A process-focused plant opts for considerable machine flexibility by choosing general-purpose equipment. Resource flexibility, if effective, can be an attractive alternative to two other types of buffers, inflated inventories and costly capacity cushions. Our simulation results, using factor settings established earlier by a panel of managers, show that resource flexibility is indeed an effective buffer against uncertainties such as end-item demand variability, capacity bottlenecks, equipment failures, and yield losses. Machine flexibility is especially helpful in environments characterized by high uncertainties, tight capacities, and large lot sizes. Worker flexibility has a similar, but less dramatic, impact. Benefits are most striking with customer service, rather than with inventory or labor productivity. Finally, we show that simultaneous introduction of both machine and labor flexibility yields only marginal improvements over either kind of flexibility alone.     

A Framework for Examining the Interface between Operations and Information Systems: Implications for Research in the New Millennium*

Even though much research has been published in operations and information systems, both functional areas find their roots in other disciplines. While operations management evolved from operations research in the 1960s, the field of information systems is of more recent vintage and traces its original roots to computer science. Both disciplines now naturally have come closer together as information and process-technology-based changes force manufacturing firms to become more efficient and customer focused. Market and technology-driven e-commerce initiatives that are likely to dominate business strategies in the future cannot be successfully achieved without a successful integration of operations and information systems. In this paper, we present a unifying framework that can be used to better understand the management of the functional interface between operations and information systems. We also categorize and highlight the contributions of the articles that appear in this special research focus issue. Finally, research directions that emerge from our understanding of this interface are outlined in an effort to stimulate further thinking and research that can advance our knowledge of this interface area.     

Release velocities and bowler performance in cricket

There is a widespread notion in the cricketing world that with increasing pace the performance of a bowler improves. Additionally, many cricket experts believe faster bowlers to be more effective against lower order batters than bowlers who bowl at slower speeds. The present study puts these two ubiquitous notions under test by statistically analysing the differences in performance of bowlers from three subpopulations based on average release velocities. Results from one-way ANOVA (and its modified versions), for international test matches, reveal faster bowlers to be performing better, in terms of Average and Strike-rate, but no significant differences in the Economy rate and Dynamic Bowling rate. Faster bowlers were found to be more effective in taking wickets of lower and middle order batters as compared to bowlers with less pace. However, there was no statistically significant difference in performance of Fast and Fast-Medium bowlers against a top-order batter.     

Do Schooling and Work Empower Women in Developing Countries? Gender and Domestic Decisions in Sri Lanka

Our work challenges and points out the limitations of the theoretical presumptions underlying the relationship between empowerment, education, and employment that have been emphasized in both the exiting literature and the current rhetoric to empower women in developing countries. We use survey, life history, and focus group data to empirically examine the relationship between schooling, paid work, and power in domestic decision making for young, married women in Sri Lanka. We argue that the relationship between education, work, and women's control of household decisions is conditioned by the larger social context, and as such, it is likely to reflect the extent to which the division of labor and access to information and economic resources are the bases of domestic power in the society under consideration. Our results make a strong case for the need to move away from broad-based conceptualizations of women's empowerment to a consideration of the specific arenas and dimensions along which women can have power. In focusing on the domestic arena alone, we find that there are important differences in both the nature and determinants of the financial as opposed to the social and organizational dimension of power in Sri Lankan households. Women who control one of these aspects of family decisions do not necessarily control the other, and while education and employment play an important role in determining women's input in financial decisions, they are largely immaterial in determining household decisions related to social and organizational matters. Our results also demonstrate the importance of going beyong simplistic and limited measures of schooling and work to consider more fundamental structural factors involving family, social, and economic organization.     

The Differential and Contingent Impact of Concurrency on New Product Development Project Performance: A Holistic Examination*

This article comprehensively examines how the four facets of new product development (NPD) concurrency, consisting of process and product concurrency groupings, influence NPD project performance under the five contextual conditions of (i) location of product in family stream, (ii) project size, (iii) stage in the product life cycle, (iv) innovativeness of the product, and (v) predictability of market demand. Using data from a large sample of NPD projects in multiple industries, there is support for this hypothesized four‐faceted structure of concurrency, consisting of process and product concurrency groupings, thereby contributing new knowledge to the concurrency literature. All four facets of concurrency display a contingent impact on NPD project performance, even though individual effects vary according to the specific contextual variable under consideration. In particular, the process concurrency facet of dynamic iterative routines was universally effective across all five contextual variables, while the product concurrency facet of cross‐functional coordination was effective in significantly influencing at least one NPD project measure. This article also reports similar, but less strong, contingency patterns, with respect to the process concurrency facet of the implementation of downstream coordination and the product concurrency facet of the use of computer‐based integrated design tools. Theoretical and practical implications of our results are also offered.     

Important Strategic and Tactical Manufacturing Issues in the 1990s*

This paper reports the identification and ranking of major manufacturing issues that American manufacturing managers and academics must focus on and resolve in the 1990s to be competitive on a global basis. Vice-presidents of manufacturing from over 75 companies across the United States were asked in a Delphi study to rank the key strategic and tactical issues facing American manufacturing in the next three to five years. Based on three rounds of a Delphi study, quality management, manufacturing strategy, and process technology emerged as the top ranked strategic issues. The top ranked tactical issues were quality control, manufacturing planning and control systems, and work force supervision. These issues were valid across diverse industry groups, since the industrial and educational background of the respondents was shown to have no impact on the final consensus rankings and opinions reported in this paper. Factor analysis of the responses by the panel revealed that certain issues tend to be consistently viewed together, and were interpreted accordingly to provide insights into the ranking of issues. Apart from building a consensus among experts on key manufacturing issues of present and future importance, this study can also be helpful for setting future academic research and pedagogical priorities for the field of production and operations management.