On Time Is Part of the Spec

A part can be flawless and still sink the program. If it shows up late, or shows up short, the line stops exactly the same as it would for a defect. We spend most of our energy asking whether a part is right. We spend less asking whether it is there, in the quantity we promised, on the day we promised it. On something that has to move, those are not two questions. They are one.

When Boeing set out to build the 787 Dreamliner, it handed roughly seventy percent of the airplane to more than fifty suppliers spread across a dozen countries. The engineering was world class and the idea was sound. What broke was delivery. Sections arrived late. Some arrived incomplete, held together with temporary fasteners because the real ones were back-ordered. Assemblies that were supposed to come together cleanly needed months of rework, because the pieces had been built to schedules and interpretations that never quite lined up. The first flight slipped by more than two years. First delivery, promised for 2008, did not happen until the fall of 2011, and the delay cost billions. The airplane was not wrong. It was late. Boeing's own conclusion afterward was blunt: they had outsourced too much and lost the thread that tied all those parts back to a single date.

After years of supplying one critical component to manufacturers on five continents, here is what we have learned about the half of the job that does not show up on the drawing.

A late part and a bad part fail the same program. The line does not care why it stopped. A defect and a no-show both end with an assembly that cannot be finished and a customer who cannot ship. We treat the delivery date with the same seriousness as the tolerance, because to the program they carry the same weight.

Lead time is a promise, not an estimate. It is easy to quote a comfortable date and hope the month cooperates. It is harder, and far more useful, to quote a date you have already built the capacity to hit. A lead time is only worth what the process behind it can actually deliver on an ordinary week, not a heroic one. If a supplier's dates move every time something goes slightly wrong, that is not a lead time. It is a wish.

The dangerous shortage is the one nobody flagged. A part you know is going to be late is a scheduling problem. A part you find out is late on the morning you needed it is a crisis. The difference is not the delay. It is the warning. The suppliers worth keeping tell you early, while you still have room to move, instead of quietly hoping to catch up before you notice.

Capacity you cannot see is capacity you cannot count on. Anyone can deliver when the month is easy. The real question is what happens when demand jumps, or a machine goes down, or two programs need the same part in the same week. Depth, cross-trained people, and a second way to make the part are invisible right up until the day they are the only thing keeping your line running.

A good supplier is boring on the calendar. The best delivery record is the one you never think about. Same part, right quantity, on the date agreed, run after run, until you stop checking because you no longer need to. That is not luck, and it is not a sprint at the end of every month. It is planning and capacity doing their job quietly.

The question worth asking any supplier is not only whether they can make the part. It is whether they can make it again next month, on the day they said, in the quantity you agreed, without you having to call and ask. On something that moves, that is not logistics. It is part of the spec, and it is every late night you never have to spend explaining to your own customer why you came up short.

The Brown Company