Ledgr/Documentation/Material planning

Material planning (MRP)

Answers one question for every item you stock: given what is on the shelf, what is already on order and what has been promised to customers, what must I make or buy, and when.

Before the first run

MRP is arithmetic over your own data, so it is only as good as three things you set up first:

1. Recipes for everything you make

   See bills of materials, and clear the Issues tab.

2. Item planning on every component

   Make or buy, lead time, safety stock, order multiple. Without these MRP has no basis for a date or a quantity.

3. Demand it can see

   Open sales orders and unfulfilled invoice lines are demand automatically. Anything you expect but have not sold yet goes in as a forecast — see below.

Run the plan

1. Material Planning → Run MRP

   Choose the horizon — how far ahead to plan. A run does not change anything on its own; it produces suggestions you then accept or ignore.

2. Read the planned orders

   Each row is "make this / buy this, this much, starting this day". The start date is the need date less the lead time, so an order dated in the past is telling you it is already too late — that is a signal, not a bug.

3. Check the time-phased grid

   Per item, per period: opening stock, demand, supply and projected closing balance. It is the clearest place to see a shortage building three weeks out while today still looks comfortable.

4. Use pegging to ask "why"

   Every planned order can be traced back to the demand that caused it. Before you commit money to a suggestion, peg it — the answer is sometimes a single order you already know has been cancelled.

Firm the suggestions

A planned order is a suggestion. Firming it is the commitment.

• Firm freezes the order so the next run leaves it alone. Do this when the decision is made but the paperwork is not raised yet.
• Convert turns it into the real thing — a work order for a make item, a purchase requisition or order for a bought one. From there it lives in procurement or on Production.
• Cancel dismisses a suggestion you have judged wrong. It will come back on the next run if the underlying demand is still there, which is usually the right behaviour.

Work orders

Converting a make recommendation raises a work order. From that point it belongs to Production — its Work orders tab is where it is released, worked and completed. Material Planning shows the open count, not the list.

1. Release

   The order moves from planned to released — it is now expected to happen, and the recipe is pinned to it so a later change to the bill does not silently rewrite an order already on the floor.

2. Complete

   Enter how many were actually built. Ledgr consumes the components from stock and receives the finished units in, at the rolled-up cost. You can complete part of an order and come back to the rest; it stays in progress until the full quantity is done.

3. Cancel

   Abandons an order that has not been completed. A completed one is reversed rather than cancelled, so that the stock movements it made are reversed too.

Forecasts

Demand you expect but have not sold. A forecast is entered per item per period and is treated as demand by the run, which is how a seasonal build-up gets planned before the orders arrive. Forecasts are yours to maintain — Ledgr does not invent them, because a number the system made up is worse than no number when it drives purchase commitments.

Run history

Every run is kept with its parameters and its results. Two runs a week apart, side by side, are the fastest way to see what changed and why the plan moved.