Changeover

A changeover is the process of switching production from one product or part number to another on a machine, such as a stamping press or molding machine, or across a series of linked machines like an assembly line, by changing parts, dies, molds, and fixtures. ^[1] Changeover time is measured as the time elapsed between the last good piece in the run just completed and the first good piece from the process after the changeover. ^[1] That window typically includes clean-up, set-up, start-up, and the first-piece inspection and adjustments needed before the line is running good product B again. The standard method for cutting changeover time is SMED (Single-Minute Exchange of Die), developed by Japanese industrial engineer Shigeo Shingo and documented in his 1985 book A Revolution in Manufacturing: The SMED System. ^{[2] [3]} SMED separates internal setup, work that can be done only while the machine is stopped (such as inserting a new die), from external setup, work that can be done while the machine is still running (such as transporting the new die to the machine), and then converts as many internal tasks as possible into external ones. ^{[2] [3]} The target is to bring changeover time into the single digits of minutes, under 10 minutes. ^[2] Shingo reported reductions averaging around 94 percent across a wide range of companies. ^[3] Because every changeover is a chance to introduce variation, a standardized changeover procedure that every operator follows the same way reduces start-up scrap and defects and produces smoother, more consistent restarts. ^[3]

Key characteristics

• Switches a machine or line from one product or configuration to the next by changing parts, dies, molds, or fixtures. ^[1]
• Changeover time runs from the last good piece A to the first good piece B, including clean-up, set-up, start-up, and first-piece checks. ^[1]
• SMED separates internal setup (machine stopped) from external setup (machine running). ^{[2] [3]}
• The core SMED move is converting internal setup tasks into external ones so they happen off the clock. ^{[2] [3]}
• The SMED target is single-digit-minute changeovers, under 10 minutes. ^[2]
• A standardized changeover sequence reduces variation, start-up scrap, and defects on restart. ^[3]

How SOPX handles this

SMED only sticks if the improved changeover is captured and run the same way on every shift. SOPX captures the best-practice changeover as a visual, step-by-step SOP: you film the experienced operator running the setup once, and the AI structures it into clear numbered steps with a video clip or annotated image per step. The result is a single agreed sequence for process standardization that separates external prep from internal setup, so every operator stages tools before the stop and follows the same internal sequence after it. The SOP is available by QR code right at the machine in 50+ languages, which matters on mixed-language manufacturing and wood production lines where a missed step means start-up scrap. When the team finds a better changeover method, you record the new version and the previous one is preserved in history, so the standard improves without drifting. Run mode can confirm each setup step was actually done before the line restarts. SOPX standardizes the procedure itself; it does not time or schedule production.

Frequently asked questions