The Production Pro Timer is an adaptive time-study tool designed to bridge the gap between "Ideal Cycle Time" measured from a short sample and "Real-World Output" recorded during production. The revised model uses a wave-based allowance curve. The allowance grows during a 9-hour working shift, then resets for the next shift because the operator is assumed to start the next working day rested.
This prevents the allowance factor from growing endlessly on multi-day jobs. The factor is capped at 89% and is calculated only inside the current 9-hour shift window.
Standard stopwatch studies often capture "Sprint Speed". This is useful for the ideal unit time, but it does not fully represent the overhead of a real shift: fatigue, material handling, scanning, documentation, breaks, workstation setup, and small interruptions.
The original single rising curve could exceed realistic values on long jobs. The revised model treats each 9-hour shift as a separate fatigue cycle.
The real estimate is still calculated from ideal time plus allowance. The difference is that the allowance is no longer based on the full job duration. It is based on the current position inside a 9-hour shift cycle.
BatchRatio is used to reduce the factor when the measured sample is close to the full order quantity.
In the application code it is calculated as:
(totalQty - testQty) / totalQty.
At 9h, 18h, 27h, and every following 9-hour boundary, the model reaches the top of the shift allowance. After the boundary, the next cycle starts from the beginning again.
| Category | Description | Impact Type |
|---|---|---|
| Shift Reset | The operator is assumed to recover before the next working day or next production session. | Wave cycle, reset every 9h |
| Fixed P-F-D | Breaks, personal time, and unavoidable delay during the working shift. | Contained inside the 9h cycle |
| Batch Logistics | Material handling, tray inspection, and system logging such as FRM documentation. | Periodic / batch dependent |
| System Latency | Scanning job references, computer login, and status updates. | Repeated during production |
| Physiological | Cumulative fatigue, hydration, posture, and concentration loss during one shift. | Rising inside each shift, reset next cycle |
Algorithm reference based on a 340-unit cable assembly job:
| Ideal Time (Stopwatch) | 4.32 Hours |
| Observed Real Variance | Approximately +89.9% |
| Maximum Allowed Factor | 89% |
| Shift Cycle | 9 hours |
| Long Job Behaviour | The allowance repeats in waves instead of increasing without limit. |
This model is safer for multi-day estimates because it prevents unrealistic values such as several hundred percent allowance on long jobs. It also reflects the practical assumption that fatigue is mostly shift-bound rather than infinitely cumulative.