Janice K. Winch

Worker Cross-Training in Paced Assembly Lines

Paced or Synchronous assembly lines are a popular class of assembly systems consisting of a series of assembly stations arranged in tandem. Every job (or order) visits all assembly stations in the same sequence and spends the same amount of time (known as the production cycle) at each station. Industries such as aircraft, fire-engine, and automobile assembly have production cycles of a few hours and are labor intensive. In spite of increased automation in such industries, human capital remains the most expensive and important contributor to a flexible production system. In this article we formulate the cross-training problem on a paced assembly line with m stations (mCT). We assume that each worker possesses a number of skills referred to as a skill vector. Our objective is to schedule a set of work orders through the assembly system so as to minimize the size of the required workforce and/or the workforce cross-training costs. We analyze the complexity of mCT and identify polynomially solvable cases. A variety of lower bounds is developed based on optimization techniques. These lower bounds are used to develop a branch and bound algorithm as well as to evaluate our heuristics. A computational experiment reports the performance of all algorithms. Using these algorithms, we examine how the formation of skill vectors affects the workforce size and draw guidelines for cross-training programs in organizations with labor intensive assembly operations.

Identifying Critical Success Factors for Supply Chain Excellence

This paper presents a research framework for studying supply chain excellence, emphasizing two distinct paths of knowledge acquisition, that is qualitative inquiry through interviews with senior supply chain executives in Taiwan and quantitative inquiry through data collection from companies that operate in Taiwan. Four factors are considered as the antecedents of supply chain excellence, such as collaboration, organizational conditions, technology adoption, and operations. The authors use the grounded theory approach to further understand those four critical factors and relevant concepts. Organizational condition was ranked by our senior supply chain executives as the most important factor based on this qualitative investigation. The effect of four critical factors on organizational performance is also assessed through regression analyses, and the results help supply chain professionals in Taiwan determine which factors and concepts of supply chain management to focus on to improve business performance. Although these findings are situation-dependent, the proposed framework is different from existing literature and can be adopted in other international studies to enhance the body of knowledge on supply chain management.

Longitudinal Study of Student Dropout From a Business School

In this study, the authors identified variables that predict college student dropout from a business school. In the 1st phase of the study, they collected information from students (N = 403) in the 2nd semester of their freshman year. Then they collected dropout data from the same students 4 semesters after the first phase. The authors used point-biserial correlations to determine the relationship of each independent variable to dropout. Three factors showed a significant correlation with future dropout: 1stsemester GPA, 1st-semester average course evaluation, and perception of financial difficulties.

Improving Student Performance in a Management Science Course With Supplemental Tutorial Videos

The authors describe the implementation and assessment of supplementary online video tutorials in a management science course. The videos were a mix of existing videos curated from the web and new videos created by the instructors of the course. Students were encouraged to use the resources with grade incentives. Students who used more of these resources performed significantly better in the course. In addition, most of the students perceived the videos as helpful.

Ordering of Tandem Constant-Service Stations to Minimize In-Process Stock Cost

We study tandem ordering of constant-service stations with unlimited buffers where service at each station adds a certain value to the job. With the goal of minimizing the total expect value of the jobs in the system, we provide conditions under which some particular orderings are optimal and describe a heuristic that finds a near-optimal order for stations of arbitrary service lengths and added values.

MetaModeling and Optimizing a Reverse Logistics System

This paper shows how reverse logistics problems can be addressed using a hybrid approach that combines simulation-based metamodels and optimization approaches. Our proposed framework (1) identifies the critical reverse logistics input and output variables, (2) proceduralizes joint qualitative and quantitative analyses into a coherent model, and (3) integrates computer simulation and optimization. This integration enables academics and practicing managers to explore the problem context and enhance the effectiveness of decision making. This approach is illustrated on a reverse logistics system where regression metamodels from simulation are used in a goal programming model to minimize operational cost and waste while meeting throughput requirements.

Case-Kelly's Class Scheduling

Kelly is a senior majoring in finance at Smith University with one more semester left to go. After a graduation audit, she was told she has five more courses she needs to take: Business Strategy (MGT 490), International Finance (FIN 358), one service-learning course, and any two finance elective courses. A servicelearning course is a requirement at the university that has a community service component. Many of the service-learning courses are offered by the Computer Information Systems Department, and Kelly would like to take one of those. In particular, two courses she finds interesting are Intergenerational Computing (CIS 102T), which involves teaching senior citizens how to use the computer, and Web Design for Nonprofit Organizations (CIS 102W). After looking at the finance course offerings, she noticed four potential finance elective courses: Data Analysis in Finance (FIN 325); Risk Management (FIN 352); Options, Futures, and Swaps (FIN 356); and Fixed Instruments and Markets (FIN 359). Kelly would like to avoid morning classes because her internship requires her to work a few hours most weekday mornings. As she makes up her schedule, Kelly would like to keep in mind her priorities. Her priorities are first, the content of the course, second, the reputation of the instructor, and third, the timing of the course. She decided she will assign a rating between 1 and 5 to each course section under consideration. From the online class schedule, she has made a list of course sections offered, as shown in Table 1. All of the courses have at least two sections. Some sections meet once a week for three hours, and some meet twice a week alternating between one-hour and two-hour periods. An “hour” at Smith University is 55 minutes long. Rating the course sections, Kelly took into account three factors: content, instructor, and timing. The rating is the weighted average of the three factor ratings. She rated the content of the course based on her interest in it, using a scale from 1 (poor) to 5 (extremely interested). The reputation of the instructor is also a value from 1 to 5, coming from published student comments (http://www.ratemyprofessors.com) and word of mouth from classmates. The timing of the course is also a number from 1 to 5, and takes into account things such as the times that most of the senior class gets together in the common rooms to watch shows such as Glee, The Walking Dead, and The Big Bang Theory. Kelly wonders how to use this information to obtain a good schedule.