A job shop is a type of manufacturer that specializes in short-run, custom orders. Job shops often produce metal parts or manufacture custom equipment, and may also be involved with designing parts. They frequently don’t know when to expect customer orders, and different customer orders may require the same equipment. Scheduling and managing job production tasks to optimize lead time is usually complex, and algorithms are created to assist the process.
In the past, job shops had often been small to medium-sized organizations. This is changing because many customers increasingly ask for customized products. Manufacturers that embrace make-to-order manufacturing processes while maintaining reasonable lead times can improve customer satisfaction.
The items produced by job shops are typically designed specifically for a particular customer. In some cases, the manufacturing process will include engineering the part to customer specifications. The shop must determine which machines and operations will be used as well as the tooling required to create the part. At times, the shop may recommend the part be made from specific materials. Many tasks within a job shop require skilled metal workers and engineers.
Customer orders are frequently routed through the same shop floor machines and operations, such as grinding, honing, and jig-boring. The machines usually require a unique set up for each different customer order. Machine set up changes between orders can take substantial time, and jobs are ideally scheduled to reduce set up time.
Raw materials used in producing parts can be expensive. The job shop may choose to order these materials when needed rather than keeping them in inventory. Though this practice reduces inventory costs, it can increase lead time. Job shops usually don’t stock finished goods unless the customer has made special arrangements.
Job shops may schedule jobs based on the scheduler’s experience and common sense. Spreadsheet programs may also be used. Specific planning software applications are also common, especially in larger shops. These may be stand-alone applications or part of larger enterprise requirements planning (ERP) applications.
Scheduling work in a job shop is complicated, and this complexity has led to an algorithm called the job-shop problem, which may be a part of the scheduling calculations included in spreadsheets and applications. The job-shop problem considers factors such as the number of jobs, the operations each job requires, a set number of machines that perform one operation at a time, and the time each operation takes. Its goal is to reduce overall lead time.