Key points
- Most line stoppages for missing material are visible days in advance. The warning is just spread across emails, the ERP and a planner's spreadsheet.
- Track three dates for every open order: when production needs it, when the supplier promised it, and whether that promise has been confirmed.
- Measure days of cover against the actual production schedule, not a monthly average, and review a short shortage list every morning.
Why shortages surprise people
When a line stops because a material isn't there, the cause is rarely a mystery afterwards. A supplier moved a ship date in an email nobody connected to the schedule. An order was never confirmed. The on-hand figure in the ERP was higher than what was really on the shelf. A schedule change pulled a run forward and used up the stock early.
Each of those facts was known by someone, somewhere, days before the stoppage. The problem is that they live in different places: the purchasing inbox, the ERP, the planner's spreadsheet and the warehouse floor.
Track three dates for every open order
| Date | What it means | Where it usually lives |
|---|---|---|
| Need date | When production will run out without this delivery | Production schedule and stock levels |
| Promised date | When the supplier says it will arrive | Order acknowledgement or supplier email |
| Confirmed | Whether the supplier has actually acknowledged the order and date | Purchasing inbox, often nowhere at all |
An order is at risk when the promised date is later than the need date, or when there's no confirmation at all a few days after the order went out. Those two checks catch most shortages early.
Measure cover against the real schedule
Days of cover is how long the stock on hand will last. The common mistake is to divide on-hand stock by an average daily usage. If the schedule runs a heavy product next week, an average hides the risk.
Days of cover = stock on hand ÷ planned daily usage from the schedule
For example, 7.4 tonnes of resin on hand with a schedule that uses 2.1 tonnes a day gives about 3.5 days of cover. If the next delivery is due in five working days, there is a gap of a day and a half, however healthy the monthly average looks.
Run a short shortage list every morning
- List only the exceptions. Materials where cover runs out before the next confirmed delivery, and orders with no confirmation after an agreed number of days.
- Sort by when it bites. The material that runs out first goes to the top, whatever it costs.
- Give each line an owner and an action. Chase the supplier, split the order with a second supplier, move a run to another line, or expedite.
- Review it in five minutes at the start of the day, with purchasing and planning in the same conversation.
Don't forget maintenance spares
A breakdown becomes a long stoppage when the replacement part isn't on the shelf. Keep a short list of critical spares, such as bearings, belts, motors and seals for bottleneck machines, with a minimum quantity for each, and include them in the same morning list.
Where AI helps
The tedious part is reading every supplier email and acknowledgement, matching it to the right purchase order and noticing when a date moves. AI is well suited to that, and to recalculating cover each time the schedule changes. The decisions stay with people: which supplier to call, whether to pay for expediting, and which run to move.
How to measure improvement
- Number of line stoppages or slowdowns caused by missing material each month
- Spend on expedited freight and emergency purchases
- Buyer hours spent chasing confirmations each week
Record these for a month before you change anything, so you can see what the new routine is worth.