What each one cannot know

Not a missing feature, a missing axis

The useful list is not what the system does not do yet. Features get added. The list that matters is what the shape of the data forbids, because that never changes with a release note.

One sentence carries most of it:

The commitments system knows how many and not which version. The definitions system knows which version and not how many.

Everything below is that sentence with a price on it.

An item code has no revision

In Meranti's ERP, the woven content-and-care label is item LBL-CC-014. It has a supplier, a price, a lead time, a stock balance and two years of purchase history. What it does not have is a version. An item code in a commitments system cannot hold one.

On 3 January, Wildersmoor issued a change to the fibre-content wording on that label. The new wording is required on goods shipped on or after 1 April. Vantry Trims quoted the new label at the same USD 0.041. Dilan Perera administers Meranti's systems, and he was asked a reasonable question: new item code, or the same one?

Both answers are wrong. That is the sign you are looking at a structural problem, not a decision.

• A new code breaks the price agreement, the two years of history, the reorder point, and every open requisition that names the old code. Purchasing would start from nothing on a label whose supplier, price and specification have not changed in any way purchasing cares about.
• The same code makes the stock balance a lie. On 19 January the new delivery of 60,000 landed on top of 41,200 old ones, and the screen showed 101,200.

They kept the same code, for perfectly good reasons. The balance of 101,200 was arithmetically correct and factually meaningless. It counted two different labels as one thing, because the system has nowhere to say they are two.

What happened next needed nobody's decision. The picking list issues the oldest stock first. So the second Larkfall delivery, 6,900 pieces shipping 19 April, was labelled from the old stock. Bethan Coyle's final inspection reads the label. That is where it was found.

Every rate in that table is Meranti's own: its costed minute, its own supplier's price, and the fee its buyer's inspection body charged on this visit. They are here so you can argue with the shape. Do not carry the rates anywhere.

There is a second number, larger and quieter. After the two Larkfall deliveries, 16,600 old labels remained. From 1 April they can never be used. At USD 0.041 that is USD 680.60 of stock the balance sheet still calls stock. It sits inside a line that also contains perfectly good labels, invisible because the item code cannot tell them apart.

The definitions system cannot count

Turn the mirror round. The Larkfall's bill of materials in the PLM is exact, current and approved. It is also useless for answering a purchasing question. Every quantity in it is per garment, and every price in it is an assumption.

Ask the PLM three questions and watch it fail honestly.

1. How much of this cloth have we bought? It does not know. It knows 1.86 m a garment.
2. What did we pay for it? It knows what the costing assumed: USD 3.42 a metre, typed in on the day the style was costed. Whether an invoice was ever raised at that number is not a fact the system holds.
3. Has anyone ever bought this at all? This is the sharp one. A PLM will happily hold a fully approved bill of materials for a material that has never once been purchased, from a supplier who has never quoted it, at a price nobody has agreed. Nothing in it can notice.

That third answer is why a tech pack can specify a trim for three seasons running that the factory has never bought. Lesson 5 follows one that did.

The most dangerous row of the eight

Look at the third row on the left: a commitments system has no way of saying "provisional".

Every row in it is a commitment, so there is no field that means probably. When purchasing sets up a new material before a supplier has quoted, the lead time still has to be typed as a number. So 30 days gets typed, because a form will not accept a shrug. From that moment it looks the same, on every screen and in every report, as a lead time measured against four real deliveries.

Course 10.1 teaches the same defect at the level of a single field: a blank is honest and a guess is not. Here it arrives as a property of a whole system. It matters more here because of what sits downstream. The planning calculation does not ask where a number came from. It cannot. It has nothing to ask with.