WHAT IS SMED?
SMED (Single-Minute Exchange of Die) is a system for dramatically reducing the time it takes to complete equipment changeovers. The essence of the SMED system is to convert as many changeover steps as possible to “external” (performed while the equipment is running), and to simplify and streamline the remaining steps. The name Single-Minute Exchange of Die comes from the goal of reducing changeover times to the “single” digits (i.e., less than 10 minutes).
SMED BENEFITS
A successful SMED program will have the following benefits:
- Lower Manufacturing Cost: faster changeovers mean less equipment downtime
- Smaller Lot Sizes: faster changeovers enable more frequent product changes
- Improved Responsiveness to Customer Demand: smaller lot sizes enable more flexible scheduling
- Lower Inventory Levels: smaller lot sizes result in lower inventory levels
- Smoother Startups: standardized changeover processes improve consistency and quality
Changeover times that improve by a factor of 20 may be hard to imagine, but consider the simple example of changing a tire:
- For many people, changing a single tire can easily take 15 minutes.
- For a NASCAR pit crew, changing four tires takes less than 15 seconds.
Many techniques used by NASCAR pit crews (performing as many steps as possible before the pit stop begins; using a coordinated team to perform multiple steps in parallel; creating a standardized and highly optimized process) are also used in SMED. In fact, the journey from a 15-minute tire changeover to a 15-second tire changeover can be considered a SMED journey.
