When to lock the design: a checklist for SOP-bound EV programs
The trade-offs around design freeze, tooling and validation — and the questions to ask before you commit steel.
The most expensive decision
Design freeze is the most expensive decision in a program, and it's almost always made under pressure. Freeze too early and you tool a vehicle you don't believe in yet. Freeze too late and you push SOP, miss the season, and burn runway re-validating changes.
The four-question checklist
Before we sign off a freeze with a client, we walk a short checklist: are the DV results in and trending the right way, is the BOM costed against real supplier quotes (not estimates), is the homologation plan aligned with the current variant table, and is the assembly sequence proven on at least one pilot build.
What 'soft' means downstream
If any of those four are still soft, freezing the design just moves the risk downstream — usually into tooling rework, which is the worst place to discover a problem. We'd rather hold the freeze by two to four weeks and protect the SOP date than 'commit steel' on a chassis we already know wants another revision.
A healthier framing
Design freeze is not a milestone you hit on a Gantt chart. It's the moment you can defend, on paper, that the next change is cheaper to absorb in production than to engineer out now.
Working on a program like this?
We help OEMs and venture-stage teams take EV programs from sketch to production.
Talk to LAND Labs