SOURCE:

Faculty: Engineering
Department: Industrial And Production Engineering

CONTRIBUTORS:

Igbokwe, N. C.
Godwin, H. C.

ABSTRACT:

An optimal maintenance strategy for improved cost and machine reliability in food manufacturing has been carried out. A mixed integer non-linear multi-objective programming model was developed in this study to minimize total maintenance cost and maximize system reliability. Four solution techniques are proposed in this study in solving the optimization model, namely, Lingo, GAnetXL (a decision support system for spreadsheet models), Genetic Algorithm and Simulation based optimization. The developed optimization model was validated by an industrial applied case study. Failure time parameters and cost data were obtained from the food manufacturing firm. The data obtained were applied to the mixed integer non-linear multi-objective optimization algorithm developed in this study, and solved using the four solution techniques. At 50% optimal reliability, Simulation based optimal solution was considered to be poor at a cost solution of N9,010,493 and reliability of 97.8% when compared with Lingo(cost: N7,593,578, reliability: 97.2%), GAnetXL (cost: N7,349,397, reliability 97.5%) and Genetic Algorithm (cost: N7,757,360, 97.83%), as it scheduled more of corrective maintenance actions which is deemed very expensive and did not add any optimal value to the reliability of the system under study. Overall, the developed optimal maintenance strategy provided better cost savings and improved system reliability than the current maintenance cost and machine reliability of the industrial case study (cost: N9,207,979, Reliability 93.82%). In terms of cost, GAnetXL provided a better optimal method with improved system reliability while in terms of reliability, Genetic Algorithm had better system reliability with an improved cost and this solution technique was adopted as a model base for the generic user interface support system developed to assist in easy implementation of the optimization model developed in this study for facilitating maintenance strategy decisions. In general, the developed optimal strategy would serve as a practical tool for adoption by food manufacturing companies and other manufacturing sectors in order to achieve optimum levels of system reliability while maintaining minimum cost expenditure through an efficient maintenance schedule. Hence the optimal maintenance schedules can be used to control stock levels of components at an efficient level.