SMED vs. TPM: Setup Time vs. Machine Uptime—What’s Your Priority?
Plus 2 Quotes and 1 Quiz to kindle your thoughts
1 Article for the Week:
This Article compares two lean manufacturing tools: SMED (Single-Minute Exchange of Dies) and TPM (Total Productive Maintenance). Both aim to improve efficiency on the shop floor, but they tackle different problems—SMED focuses on reducing setup/changeover time, while TPM emphasizes maximizing machine reliability and uptime. The confusion often arises because both involve equipment and downtime, yet their approaches and outcomes differ significantly.
SMED (Single-Minute Exchange of Die)
Purpose: Minimize the time it takes to switch a machine from producing one product to another (e.g., changing a die in a press).
Goal: Achieve setups in "single minutes" (under 10 minutes), boosting flexibility and reducing batch sizes.
How It Works: Breaks setup time into Internal (done while machine is stopped) and External Activities (done while running) tasks, then streamlines or offloads internal steps.
Example: A CNC machine switching from cutting Part A to Part B—SMED cuts the 30-minute changeover to 5 minutes.
Benefits: Faster production runs, smaller batches, less idle time. Less WIP and better Delivery Performance due to Load Levelling.
When to Use: High variety production with frequent changeovers and high Changeover times
TPM (Total Productive Maintenance)
Purpose: Maximize equipment effectiveness by reducing breakdowns, defects, and downtime.
Goal: Achieve zero unplanned stops through proactive maintenance and operator involvement.
How It Works: Uses 8 pillars (Autonomous maintenance (operators care for machines), planned maintenance, etc) and tracking Overall Equipment Effectiveness (OEE).
Example: A lathe with regular oiling and checks avoids sudden failures, maintaining 95% uptime.
Benefits: Longer machine life, higher quality output, fewer interruptions.
When to Use: Regular Breakdowns of machines, poor utilisation of machines
Why It Matters
Choosing between SMED and TPM—or combining them—depends on your shop’s pain point:
High Changeover times & Frequent Changeovers - Use SMED
Poor Reliability of machines, high Downtime - Use TPM
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2 Quotes for the Week by Taiichi Ohno:
"To implement the Toyota Production System, you must understand that the purpose is to reduce costs by eliminating waste—nothing more, nothing less."
"Why not make the work easier and more interesting so that people do not have to sweat? The Toyota style is not to create results by working hard. It is a system that says there is no limit to people’s creativity."
1 Quiz for the Week:
In a pull system, what happens when downstream demand decreases?
a) Production continues at the same rate
b) Inventory is stockpiled
c) Production slows or stops
d) Upstream processes double output
Share your reply for the quiz and get featured in the next week’s newsletter.
VERY GOOD INSIGHTS
Answer for the Quiz: c) Production slows or stops