MINIMIZING TOTAL TARDINESS AND CREW SIZE IN LABOR INTENSIVE CELLS USING MATHEMATICAL MODELS
This thesis attempts to provide solution to some of the real world issues in cellular manufacturing, namely manpower allocation and cell loading. Although significant work has been done in these fields, research to minimize the Total Tardiness (TT) within a multi – cell environment has been limited. The methodology adopted in this thesis is a two-step one. Firstly, manpower allocation for operations within a cell is determined using mathematical models. Traditional mathematical models for finding the number of operators to be assigned for an operation have been expanded to be able to determine the individual operators to be assigned for each operation. This step also includes variations of the mathematical model for sharing of operators between operations and sharing of operators with restrictions. The models with little or no restrictions have found to yield a higher production rate than the model with no operator sharing allowed. The same model has been extended to introduce operator skill levels as well. The next step involves developing and testing mathematical models for cell loading. The performance measure examined in this phase is the Total Tardiness subject to total Crew Size restriction. The Total Tardiness is reduced by increasing the Crew Size. In addition, the crisp mathematical models have been adapted to solve a bi-objective problem for minimizing the Total Tardiness and the Crew Size using fuzzy sets. The results indicate that the fuzzy math models offer a good alternative in terms of accuracy to the optimal solution, as well as the computation time.
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:mathematical modeling cell loading scheduling total tardiness crew size manpower allocation
Date of Publication:01/01/2007