A faster individual machine does not automatically increase throughput. First identify the section that actually constrains material flow.
Observe the entire line
Record waiting times, buffer levels and recurring interruptions throughout the process. A station often waiting for material differs from one with parts accumulating ahead of it. Both may appear slow but have different causes.
Consider product mix and shifts
The constraint can change with product variant or shift. Relate observations to actual production conditions. Tool changes, missing approvals and incomplete preparation can limit flow just as a technical cycle time can.
Use overall throughput as the measure
After a change, check whether the line produces more good parts. Larger intermediate buffers alone do not demonstrate improvement. Record whether the bottleneck has been removed or moved to another station.