How do I know what lead time I should use?

1. Open a line that has a supplier and no lead time, and press Edit, the pencil. Under Lead time a grey note says, for example, Usually 4 weeks from Vinidex, over 3 deliveries.
2. Press Use 4 weeks to put it in the box, then Save. The order-by date then counts back from it. Nothing is saved until you press Save.
3. The figure comes from your own deliveries from that supplier, on every job. It counts from the day you first sent the order to the day the line was marked delivered.
4. YourCA takes the middle figure, so one odd delivery does not move it, and rounds up to whole weeks.
5. It shows only after three deliveries that have both an order date and a delivery. Below that it shows nothing, because a guess is worse than a blank.
6. Once the line has a lead time, the suggestion goes away. Type over it at any time.