## Set the plan-wide defaults

The **Planning assumptions** card holds the default policy every part starts from. Each numeric field saves when you leave it.

| Field                       | Effect on the plan                                                                  |
|-----------------------------|------------------------------------------------------------------------------------|
| **Spare quantity**          | Adds that many units to every net requirement.                                     |
| **Minimum stock**          | Floors the requirement so that many units stay on hand.                            |
| **Yield rate (%)**         | The expected good-output rate assumed when sizing requirements.                   |
| **Attrition rate (%)**     | Inflates buy quantities to cover expected scrap.                                   |
| **Buffer lead days**       | Extra schedule buffer on top of each part’s lead time.                            |
| **Order offset days**      | Adjusts order timing by that many days.                                           |
| **Period of supply (weeks)**| Consolidates that many weeks of demand into one order.                            |
| **Minimum batch quantity**  | Rounds each order up to the next multiple of this quantity.                       |

The **Lead-time strategy** selector controls where lead times come from. **Category defaults** uses standard lead times per part category, and **Manual / CSV** uses values you supply. Strategies based on procedure steps and historical runs appear in the list but are unavailable until that data exists.

## Review each part’s resolved policy

The **Per-part policy** panel lists every part in the plan’s bill of materials with the policy that applies to it. For each part you see:

- The requirement delta, for example “Required 12, with policy 14”, so a policy value never changes a quantity silently.
- One statement per active field, such as the spare quantity added to the net requirement or the minimum batch quantity the order rounds up to.
- Provenance chips showing where each value came from, such as a category default or a CSV upload. A part with no policy adjustments uses its gross requirement as-is.

These per-part numbers are previews. The authoritative quantities and dates come from running the plan.

## Edit policies per part via CSV

Per-part overrides are edited in bulk through a CSV round trip:

1. In the **Per-part policy** panel, click **Download CSV**. The template lists every part with its current category-prefilled values.
2. Edit the values you want to override. A field you leave blank keeps the plan default for that part.
3. Click **Upload CSV** and select the edited file. The panel updates each part’s resolved policy and marks the uploaded values’ provenance.

## Correct a part’s make or buy classification

A related per-part setting lives on the **Components** tab: each part’s **Make / Buy** value, which decides whether Autoplan proposes a purchase order ( **Buy**) or a run ( **Make**) for its shortfall. Change it from the dropdown on the part’s row; the plan re-derives immediately.