Configuring flexible flowlines

Document Type


Date of Original Version



Flexible machines are machines equipped to respond to a variety of jobs by the selecting appropriate tools, which are available on the machine, to match the tasks required for each incoming job. Computer Numerical Control machines (CNCs) and robots with multiple grippers are examples of such machines. However, the tool holding or tool magazine capacity usually limits the flexibility of these machines. A sequence of such machines, with directed flows, is a flexible flowline, and these are seen as a possible solution for producing large varieties of similar products. In this paper, problems related to configuring flexible flowlines are considered, with the goal of minimizing the line size without requiring any backtracking while processing parts. Several forms of the problem are considered. Scenarios where single part types are produced on identical, tool-magazine capacity limited machines are examined first. These are expanded to include restrictions on processing capabilities as constraints. Multiple-part type scenarios are then modelled, beginning with procedures addressing open magazines, finally followed by restricted machines, with tool magazine size limitations. A mathematical programming formulation for configuring such a line is detailed, and solutions for test cases presented.

Publication Title

International Journal of Production Research