1.3 SHOP FLOOR CONTROL
• No factory is perfect, and a schedule can become invalid at any time because of,
- Machine breakdown
- Sudden material shortage
- Workforce vacancy
- Tool breakage
- etc.
• What to do about it,
- Wait and See
- Try to find alternative production plans/parts
- Ask engineering for replan
- Bump other jobs
- ?????
1.3.1 Shop Floor Scheduling - Priority Scheduling
• Instead of scheduling before production (MRP and Capacity planning), a manufacturer may opt to do scheduling on the fly.
• Some of these methods include,
- Earliest operation due date - soonest date. This gives time until due, but ignores processing time.
- Order Slack - soonest date minus processing time. This gives the amount of time to play with.
- Shortest operation first - Do the quickest jobs first. This just clears out WIP faster.
1.3.2 Shop Floor Monitoring
• It is important to know what is happening on the factory floor.
• To do this we must pay attention to obvious problems like machine operation, and hidden problems such as quality, and production quantities.
• Inspection covers a number of areas,
- Inspection of raw materials
- Inspection of manufactured product
- preprocess
- in-process
- post process
- Inspection of production process parameters
- tools
- fixtures
- production machinery
- Verification/calibration
- inspection fixtures
- Inspection gauges
- Inspection machinery