Work Scheduling in Flexible Manufacturing Systems under Tool Availability Constraints
Some of the planning problems in flexible manufacturing systems (FMS) are introduced and the impact of tooling considerations is observed. The effects of tool variety, product variety and product similarity on the frequency of two types of tool change, due to product variety and due to tool wear, are identified. It is shown that when variety is great, tooling availability constrains scheduling decisions.
The problem area is illustrated with reference to an example FMS, for which it is shown that tool capacity constrains scheduling decisions. The possibility of developing a part launch sequence which would minimize the need for tool changes is considered but was found ineffective. Dynamically selecting jobs from queues so as to minimize tool change is also found to be ineffective. A linear programming model5 is described, but it was found to require further evaluation.
A tooling post-processor for a simulation model is presented which computes the number of tool changes in any work schedule. For the FMS considered it is found that the number of tool changes due to product variety is small compared to those due to tool wear. It is concluded that the assumptions underlying some of the FMS planning problems must be reconsidered in view of this result.
KeywordsTool Wear Product Variety Work Schedule Flexible Manufacturing System Automatically Guide Vehicle
Unable to display preview. Download preview PDF.
- Stecke K E (1981) Production Planning Problems for Flexible Manufacturing Systems, PhD Dissertation, Purdue University, West Lafayette, USA.Google Scholar
- Carrie AS & Adhami E (1983) Introducing an FMS by simulation. Proceedings of 2nd International Conference on Flexible Manufacturing Systems, London, October, IFS Publications, Bedford.Google Scholar
- Menon U & O’Grady P J (1984) A flexible multiobjective production planning framework for automated manufacturing systems. Engineering Costs and Production Economics.Google Scholar
- Carrie A S & Petsopoulos A C (1985) Operation sequencing in an FMS. Robotica, 1.Google Scholar