What Is SMED and Its Importance?

What Is SMED and Why Is It Important?

LEAN principles are all centered on process improvement, which ultimately leads to improved efficiency and, thus, higher profitability. The concept is simple, but getting there is usually harder that one can imagine.

One of the vast building blocks of Lean relates to quick changeover setups. The faster the changeover time, the less downtime of equipment. Remember - DOWNTIME is the definition of the Eight Deadly Wastes of a manufacturing environment.

The key to a quick changeover setup is termed SMED. SMED stands for Single-Minute Exchange of Die. The SMED system is a theory and set of techniques that make it possible to perform equipment setups and changeover operations in less than 10 minutes – in other words, in the single-minute range. SMED principles can be used and applied in almost any operation or process. It was developed to improve die and machine tool setups.

SMED’s goal is to reduce the setup time to within minutes. Depending on the process, setup within minutes may be very difficult. However, in most cases, if the SMED principles are followed, drastic reductions in setup time can be obtained.

The basic principles of SMED are:

• Identify internal versus external changeover tasks.
• Analyze each task’s real purpose and function.
• Focus on no/low cost solutions.
• Aim to eliminate changeover time.

You may ask, how do I go about this process? SMED is typically broken down into three stages. Each stage has specific tasks and objectives, and all are interrelated and work together. These stages are outlined below.

Stage 1 – Separate internal and external setups

Certain tasks can clearly be done before machines are stopped for changeover. These include lining up the right people, preparing parts and tools, making repairs, and bringing the parts and tools closer to the equipment. There are three practical techniques to doing this:

• Develop and implement changeover checklists.
• Perform function checks on parts and tools.
• Reduce transportation on tools, parts, and materials.

By separating these tasks and performing them as external setups, changeover time can be cut by as much as 30% to 50%.

Stage 2 – Convert internal setups to external setups

Stage 1 functions alone will not reduce the internal setup time to within the single minute range. For that, you must implement Stage 2. There are two primary steps to Stage 2:

• Look at the true functions and purposes of each operation in your current internal setup.
• Find ways to convert these internal setups to external setups.

The key to the successful implementation of Stage 2 is to look at the function as if you are new to it. Three practical techniques help shift internal setup tasks to external setups. Those techniques are:

• Preparing operating conditions in advance.
• Standardizing functions.
• Using intermediary jigs.

Stage 3 – Streamline internal and external elements

In this third and final stage, all of the remaining internal and external setup operations are improved. This can be done by looking closely at each operation's function and purpose one more time. More specifically, Stage 3 improvements can be divided into external and internal setup improvements. Four basic approaches to accomplishing this are through:

External Setup

• Maintain a visually organized workplace

Internal Setup

• Implement parallel operations
• Eliminate the need for adjustments
• Use functional clamps
• Mechanize functions

SMED provides many benefits for companies and employees. More specifically, the advantages of SMED, along with quicker and more efficient setup times, are improved flexibility, speedier delivery, better quality and higher productivity. Through these benefits, you will also see simpler setups and safer changeovers, less inventory, and more standardized processes.