The Vehicle Development Process

Vehicle development is the V-model from Module 1, fleshed out across years. Down the left arm, requirements are set and designed: vehicle-level targets (mass, performance, range, crash, cost) are defined, then cascaded down into subsystem targets (powertrain output, body stiffness, cooling capacity) and component specs (spring rate, gear ratio, motor power). Design proceeds subsystem by subsystem, increasingly detailed and increasingly digital (CAD, CAE simulation) before any metal is cut. At the bottom of the V, components are built and tested. Up the right arm, verification (does each part meet its own spec?) and validation (does the whole vehicle meet the original vehicle-level targets?) climb back up through integration, prototype builds, and real-world testing, until the car is signed off for production. Program gates control each transition, freezing the design at increasing levels of commitment.

A typical program runs three to five years through a sequence of prototype builds (often named A, B, C samples of increasing maturity) separated by gates that freeze the design at each level. Early prototypes (mules, A-samples) test subsystems in isolation or in borrowed bodies; later ones (B, C) are near-production vehicles for durability, crash, and emissions validation. Simulation (CAE) front-loads as much as possible — a crash simulation costs a fraction of a physical test — but physical validation remains the sign-off authority. The timeline is dominated by long-lead tools (body-stamping dies, injection moulds) which must be committed early and are expensive to change, which is why late design changes are so costly and why the gates enforce freezing.