A multi-period multi-floor plant layout problem with stochastic workflow between facilities and constraints due to varying areas of facilities

• Main Authors: Chong, Iris, Leung, Irene, Sy, Evamarie
• Format: text
• Language: English
• Published: Animo Repository 1996
• Subjects: Plant layout; Stochastic processes; Production engineering; Assembly-line methods
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/9640
• Institution: De La Salle University

Due to the growing competitiveness in manufacturing, one of the main concerns is the optimum use of space and facilities to reduce unnecessary costs. In a plant or factory, workflow exits when several facilities (machines and equipment) are operated to produce a product. Facilities Layout Problem is concerned with the proper location of different facilities to various sites, or to a floor area in order to minimize the material handling cost incurred for transporting materials from one facility to another. Poor layout results in a substantial material handling cost, which consumes a big percentage of the total operating cost. The existing multi-period plant layout models with stochastic workflow between facilities failed to simultaneously incorporate the multi-floor scenario with space allowances between facilities. Likewise, this study is based on the works of Caluag, Dela Cruz, and Lima (unpublished, 1995) on the multi-period stochastic model with addition of new facilities and space constraints, Bozer, Meller & Erlebacher on the multi-floor plant layout problem, and Lacksonen (1994) on the varying areas of facilities in a multi-period Multi-Floor Plant Layout Problem with Stochastic Workflow Between Facilities and Constraints Due to Varying Areas of Facilities. Due to the scarcity of land, resulting to the rapid escalation of its price, more and more companies construct multi-floor buildings as their factory. It is for this reason that the multi-floor scenario is deemed significant to include in the model. Another unique feature of this research is the application of a different method of locating facilities other than the traditional Quadratic Assignment Problem. In the grid line approach of lay outing, there is no predetermined sites, so the decision maker is given a free hand in creating various space sizes for different facilities in a floor area. Determination of the facility's presence is defined by coordinate points in a floor area divided by grid lines, similar to the Cartesian Plane. A job-shop with multiple product operating multiple facilities is used as a reference for this research. The objective of the model is to minimize the total cost which consists of : material handling cost, fixed cost, set-up cost, transfer cost, and downtime cost incurred in arranging the facilities. The general constraints taken into account are the space, movements of facilities within a floor, non-overlapping, and allowance constraints. The resulting quadratic model is validated through job shop plant layout problem using the Solver function of Microsoft Excel 7.0 for Windows 95. Simulation results reveal that the model can generate optimal solutions for multi-period, multi-floor plant layout problems with stochatic workflow between facilities and constraints due to varying areas.