SMED (Single Minute Exchange of Dies)

WHAT IS SMED?

SMED (Single-Minute Exchange of Dies) 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 Dies comes from the goal of reducing changeover times to the “single” digits (i.e. less than 10 minutes).A successful SMED program will have the following benefits: Lower manufacturing cost (faster changeovers mean less equipment down time) 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)

BASICS OF SMED

SMED was developed by Shigeo Shingo, a Japanese industrial engineer who was extraordinarily successful in helping companies dramatically reduce their changeover times. His pioneering work led to documented reductions in changeover times averaging 94% (e.g. from 90 minutes to less than 5 minutes) across a wide range of companies.

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.

In SMED, changeovers are made up of steps that are termed “elements”. There are two types of elements:

Internal Elements (elements that must be completed while the equipment is stopped) External Elements (elements that can be completed while the equipment is running)

The SMED process focuses on making as many elements as possible external, and simplifying and streamlining all elements.

SMED (Single Minute Exchange of Dies)

The SMED system has three major phases as shown above. These phases are performed in sequence and the entire sequence can be iterated (repeated).

Few Examples for SMED:

Pit crew changeovers in auto racing, especially with the tires 

-presorting laundry as you take it off...colors together, whites together, delicates together, etc....do this ahead of time and you completely eliminate the post sorting activity when it is laundry time 

Cooking - if you have the time to watch some cooking shows, they do a lot of external setups to fit all of it into a 1/2 hour show...and even basic cooking at home, nobody preheats the oven and waits until it is fully heated before they start mixing ingredients - they mix the ingredients while the oven is heating up 

Drive thru at fast food places - they've really increased their output over the years including one small step: telling the customer how much they owe before they get to the window to pay. That allows you to get your money ready while you are waiting in line - that saved them seconds per order which in turn - allowed them to serve many many more people per day. 

Slowly emerging in grocery stores are the use of the self scan devices that allow consumers to scan all of the items in their cart before reaching the checkout line and then you scan one barcode and it downloads your entire cart worth onto one bill and you pay. in the future, they will be switching (possibly) to all RFID tagged items that as soon as you put them in your cart and walk out the door, it scans the whole cart and bills your credit card on file. No more waiting in a checkout line!