This proposal models the effects of job rotation, in terms of learning and forgetting, on the overall productivity of a group of workers. This reveals the cross-training tradeoff between worker flexibility versus potentially reduced efficiency. The research combines experimental psychology (leaning and forgetting curves) with robust mathematical programming and optimization methods to develop tools that could be of significant use to managers. The three research questions will be answered with the aid of computer simulation and validated in the field. The broad impact is the potential for enhancing productivity and improvements in the work environment that will benefit the economy.
Modern manufacturing practices, which often use cellular designs and just-in-time operations, may disrupt the continuous learning process. While in the past managers relied on specialization over long production runs to improve productivity, today they often make use of cross training in an attempt to manage rapidly changing technology and uncertain demand. However, at present, no concrete guidelines exist to aid managers in deciding levels of cross training, task rotation, and the sequencing of jobs. The objective of this research is to improve productivity in organizations with job rotation through assignment and scheduling of workers to tasks and to examine preferred assignment and cross training levels in this environment. Based on individual learning and forgetting characteristics, workers are assigned and scheduled to tasks in ways designed to maximize productivity. An important contribution of the project is understanding the tradeoffs between lost productivity due to reduced specialization and the flexibility benefits due to cross training.
The study will address the following research questions: 1. Within a work group, to which of m tasks should each of n workers be assigned for three objectives a.) Maximize throughput given n workers, b.) Minimize the number of workers needed for a given production requirement, c.) Minimize the time required for n workers to meet a given production requirement. 2. What degree of cross training should be allowed or required, including: a.) How many tasks in addition to the initial assignment should the n workers be responsible for? b.) How often and in what pattern should workers shift between these cross trained tasks (i.e., what is the schedule)? 3. What are the effects of environmental factors including, Workplace design implications (i.e., pattern of work and/or information flow), Adjacent vs. non-adjacent worker-task assignments (i.e., tour travel time costs), Single vs. multiple products, and Batch size.
First, the investigators will develop math programming based decision models for assigning and scheduling workers to tasks. The models will incorporate the effects of individual worker learning and forgetting. Second, the investigators will develop a measurement model for quantifying worker learning and forgetting for use in the math programming models. Third, the investigators will examine the research questions described above based on empirical distributions of individual workers' learning and forgetting patterns, through simulation first and then subsequently applying the results in real work settings.
The impact of this research is potentially broad, affecting directly the many service and manufacturing organizations that make use of cross training. Further, the proposed research will quantify the costs from learning and forgetting effects that are associated with cross training programs. While there are good reasons for cross training workers, many related to increased flexibility, when these workers are learning new tasks they are subject to forgetting others and productivity may suffer significantly. Thus, the research will provide both descriptive and prescriptive capabilities for organizations to quantify and plan cross training programs in manufacturing and service settings.
