Function validate_smed_setup 

pub fn validate_smed_setup(
    setup_time_before: f64,
    setup_time_after: f64,
    batch_size_before: usize,
    batch_size_after: usize,
    throughput_before: f64,
    throughput_after: f64,
    tolerance: f64,
) -> Result<TpsTestResult, String>

Validates SMED (Setup Time Reduction) effects.

TC-5: Setup reduction provides non-linear capacity gains

Setup reduction from 30min to 3min (90% reduction) with batch size reduction enables one-piece flow without capacity loss.

OEE Availability formula: Availability = (Planned Production Time - Downtime) / Planned Production Time

Errors

This function always returns Ok. The Result type is for consistency.