What a Changeover Is and What This Course Covers

A changeover is all the work needed to stop making one product and start making the next one at full rate and full quality. On a press it means changing the die. On a moulding machine it means changing the mould. On a packaging line it may mean changing the film, the format parts, the date coder and the labels. In a process plant it may mean emptying, cleaning and refilling a vessel. The words differ, but the problem is the same: while the changeover happens, the equipment makes nothing that can be sold.

Other words for the same thing are set-up, make-ready, product change and format change. This course uses "changeover" for all of them.

The method taught here is single-minute exchange of die (SMED), also called quick changeover. Its aim is to make changeovers short, predictable and safe, so that the operation can change product more often without losing capacity.

A first example

At Brenlow Engineering, an invented engineering company used in this course, a 250-tonne press makes brackets for four customers. A die change takes about 90 minutes. Because the change is long, the planner runs large batches, so the store is full of brackets that nobody needs yet, and an urgent order has to wait for the current batch to finish. The press team believes the change "cannot be faster, because the die is heavy". You will see in later modules that most of those 90 minutes are not spent moving the die at all.