The University of Maryland

Institute for Systems Research


A Master Plan for Hybrid Shop Layout

Project Overview

The overall objective of this project is to redesign the shop layout of an assembly job shop in order to reduce cycle times through reductions in material handling effort and through reduction of setup times.


We identify group technology (GT) cells, each of which consists of a set of workcenters that are required to produce a family of parts with similar manufacturing characteristics and/or setups. The objective is to reduce part moves between cells by assigning as many production tasks as possible to one cell and by sequencing production tasks in a way that similar setups follow one another. This cell formation problem does not consider any physical characteristics of the machines.

We then develop an optimal manufacturing facility design in the form of a hybrid layout. This type of layout is a mixture of pure GT cells and the individual machines that cannot be moved or placed into cells. This very realistic constraint inevitably has to be respected in a variety of shops. The objective remains to reduce cycle times by decreasing the material handling effort.

Determining the layout involves creating the intra-cell layout and the inter-cell layout. The intra-cell layout problem is solved by selecting an appropriate material handling system for the cell and then placing the machines within the cell. Solving the inter-cell layout problem determines the optimal physical location of the various GT cells and the individual machines that were not incorporated into cells but which may be grouped into functional areas.

For further information, please contact CIM Lab Manager