What is SMED? The Power of Quick Mold Change in Production
Among the processes that waste the most time on production lines, mold and equipment change is at the top. This downtime during which the machine is stopped, settings are adjusted, and it is restarted when switching from one product model to another directly affects productivity. Herein lies SMED, a proven lean manufacturing technique developed to minimize this loss.What is SMED?
SMED (Single Minute Exchange of Die) is a lean manufacturing methodology that aims to reduce mold or equipment exchange times to single—digit minutes — that is, below 10 minutes. Translated into Turkish as "One-Minute Mold Change"The concept was developed by Japanese engineer Shigeo Shingo, who worked at Toyota factories from the 1950s onwards. At Toyota, Shingo revolutionized the manufacturing world by reducing mold change times for large press machines from hours to minutes.
The basic idea of SMED is this: Analyze each step in the changeover process and start doing as much work that was previously done while the machine was stopped as possible while the machine is running.
Internal and External Setup: The Foundation of SMED
The essence of the SMED methodology is to divide the installation activities into two categories:Internal Setup (Internal Setup)
These are the actions that must be taken when the machine stops. Steps such as physically altering the mold or tightening fasteners fall into this category.External Installation (External Setup)
Preparations that can be made in advance while the machine is running. This scope includes the introduction of the new mold, preparation of tools, and pre-setting of parameters.The first and most critical step in SMED is to determine which of the existing internal setup processes can be outsourced. In the analyses carried out, it turns out that more than forty percent of the operations performed as an internal installation in most factories can actually be performed while the machine is running.
SMED Implementation Steps
1. Record the Current State Record the entire change process with video. Starting point: production of the last good part. End point: production of the first good part in the new arrangement.2. Separate Internal and External Activities Perform video analysis to list each step and classify them as internal/external.
3. Convert Internal Activities to External Ones Rearrange preparations that are currently done while the machine is stopped in a way that they can be performed while the machine is running. Steps such as preheating, pre-setting, and material preparation provide significant benefits.
4. Optimize Internal Activities Speed up the remaining internal activities as well: standard fasteners, quick locking systems, color coding, apparatuses that connect in one movement.
5. Standardize the Entire Process Convert the new developed process into a written procedure, train operators, and measure the time regularly.
Benefits of SMED
- Machine availability and OEE (Overall Equipment Effectiveness) increase
- Small batch production becomes economical; inventory decreases
- Product variety can be responded to quickly
- Operator fatigue and the likelihood of errors decrease
- Flexibility in responding to customer demands is gained