What is the difference between order quantity and schedule quantity?
Order quantity is the total the customer has ordered, sometimes for a whole year or more. Schedule quantity is the part of it the customer wants in a given period, such as this month or this week. Production should plan on the schedule quantity, and track the balance against the order quantity.
A simple case. A customer gives a purchase order for 12,000 parts for the year. In March he wants 1,000. The order quantity is 12,000. The schedule quantity for March is 1,000. These are two different numbers, and a plant that mixes them gets into trouble.
Where owners feel the problem
- The plant makes the whole order in the first three months because material was bought for all of it. Stock piles up, cash is stuck, and the customer later changes the design.
- The plant makes too little, because someone read "1,000" as the full order and forgot there was a balance.
- Dispatch says "order complete", but the balance column in the sales sheet still shows pending quantity.
- Two people quote two different "pending" numbers to the same customer on the same day.
None of these is a worker's fault. They happen because the plant has one word, "order", for two different things.
Keep three numbers apart
| Number | Meaning | Who sets it |
|---|---|---|
| Order quantity | Total ordered on the customer's purchase order | Customer, recorded by sales |
| Schedule quantity | Quantity asked for in a period, with a date | Customer's call-off, confirmed by sales and planning |
| Dispatched quantity | What has already gone to the customer | Dispatch, from the dispatch papers |
Balance to supply = order quantity − dispatched quantity. Balance for this period = schedule quantity − dispatched in this period.
Example only: order 12,000, schedule for March 1,000, dispatched so far in March 600. Balance for March is 400. Balance for the whole order is 12,000 minus everything dispatched since the start.
How the work order uses them
The work order is the thread of the factory. Each work order should link to one customer order and one schedule lot. Then every paper (material issue, job card, inspection, dispatch note) shows which lot it belongs to.
Production quantity may be a little higher than the schedule quantity, to allow for rejection and set-up pieces. Keep that extra small and written down. The balance is always counted on good pieces dispatched, not on pieces made.
Plan on the signed schedule
If the customer's buyer gives a monthly schedule, hold a short meeting each month, about the 25th. Both sides agree and sign the schedule quantity and dates for the next month. The plant then plans only against the signed schedule.
This helps in three ways.
- Material is bought for the confirmed lot, plus a safety margin, and not for the whole year.
- Capacity is checked against real monthly demand. If the schedule does not fit, you tell the customer early.
- The customer sees that you plan and keep promises.
The order tells you how much business you have. The schedule tells you what to make today.
Why a frozen balance and clear dispatch habits matter
In many plants, the pending sheet is wrong because of small habits. Someone changes the order quantity when the customer changes the schedule. Someone ignores a dispatch because it was a part delivery.
Three habits keep it clean.
- Change the order quantity only when the customer's revised purchase order arrives.
- Reduce the balance only from dispatch papers, one work order at a time.
- Show orders on hold separately from open orders, so they do not hide real pending work.
Also, if one work order is over-supplied, do not let the extra hide a shortfall in another. Keep the balance for each work order.
How to start in your plant
- Take your five biggest repeat customers. For each one, write on one page: order quantity, the schedule pattern (monthly, weekly), and the date schedules arrive.
- Add a column for schedule quantity on your order sheet, next to order quantity.
- Put the order number and schedule lot on every work order.
- Make dispatch update the balance from the dispatch papers, not from memory.
- At the monthly meeting, plan material and capacity on the signed schedule only.
Use simple words on the sheet. Write "order quantity" and "schedule quantity" in full. Short forms like "qty 74" can be misread as a work order number.
Key points
- Order quantity is the total ordered. Schedule quantity is this period's call-off.
- Plan material and production on the signed schedule, and track the balance against the order.
- Link each work order to one order and one schedule lot.
- Reduce the balance only from dispatch papers.
- Agree the next month's schedule with the customer before the month begins.
