Towards job-shop scheduling with the use of virtual manufacturing cells

The article presents the possibility to modify finding solutions when job-shop scheduling is conducted based on the idea of virtual cellular manufacturing. It is demonstrated that creation of virtual manufacturing cells for defined production orders and exploiting them in the process of job-shop scheduling allows to reduce makespan. In a virtual manufacturing cell, machines are dedicated to produce for selected production orders as in a regular manufacturing cell, but machines are not physically allocated in designated area. Virtual cell configurations are therefore temporary, and assignments are made to optimize the scheduling objective under changing demand conditions. In this research, an example of job-shop scheduling problem with embedded virtual cellular manufacturing is presented. The conditions of application of virtual manufacturing cells in terms of production flow modification are described.