MRP and production planning
MRP and production planning software calculates what to buy or make and when, based on demand, stock, lead times and bills of materials.
Planners review its output as suggestions and decide which to accept.
Key facts
- MRP produces planned orders and action messages.
- Action messages ask to reschedule in or out, cancel or expedite.
- The results depend on parameters: lead times, safety stock and lot sizing.
- Pegging explains a suggestion by tracing it from demand to supply.
What it covers
| Aspect | In this category |
|---|---|
| Output | Planned orders and action messages |
| Messages | Reschedule in or out, cancel, expedite |
| Parameters | Lead times, safety stock, lot sizing |
| Explanation | Pegging from demand to supply |
Who uses it
Planners and buyers review the suggestions every day. Managers look at the exceptions that affect customer orders, and purchasing turns accepted suggestions into orders to suppliers.
What makes it hard to design
Volume of suggestions. An exception list ordered by consequence lets planners start with what matters.
Explanation. Pegging explains each suggestion. The parameters behind a suggestion are shown next to it.
Routine acceptance. Bulk accept handles routine suggestions, so attention goes to exceptions.
A planner who cannot see why a suggestion appeared will check it outside the system. Every hidden parameter turns into a spreadsheet.
Trade-offs
- Bulk actions let users make large mistakes quickly. Without preview and undo the feature moves the risk around and saves little.
- Automatic rescheduling finds better sequences than manual placement, and planners find it hard to trust a plan when nobody can explain why a job moved.
Common mistakes
- Suggestions without the parameters behind them
- One flat list of messages without an order by consequence
- Every suggestion confirmed one at a time
- Planning screens that cannot compare orders, resources and dates at once
Related experience