A pick–orient–insert–fasten–inspect cycle moves between a parts bin, assembly jig and tool rack. Compare a long-reach bench with point-of-use placement, follow the hand path, and distinguish observed, normal and standard time.
• A 3D laboratory scene with: Operator and articulated arm; Parts bin; Assembly jig and clamped part; Suspended screwdriver and rack; Colored hand path and stopwatch. • Controls: Workstation arrangement; Hand travel speed (0.2-0.8 m/s); Performance rating (80-120 %); Allowance as fraction of standard time (0-25 %); Include two-second tool search. • Live readouts: Observed cycle time; Travel portion; Hand path length; Normal time; Standard time; Completed assemblies. • Guided experiments: Move supplies closer; Remove searching; Change the allowance convention.
• Travel time=total path distance / hand speed • Cycle = travel + pick 1 s + insert 4 s + fasten 3 s + inspect 2 s + optional search 2 s • Normal time=observed time × rating/100 • Standard time=normal time/(1−allowance/100) • Allowance is explicitly a fraction of standard time, not normal time.
Deterministic illustrative motion study, one repeated assembly cycle, constant travel speed, no acceleration or bimanual overlap. Rating and allowance affect reported standards only, not physical hand speed. No certified work standard or ergonomic safety claim. Coordinates and paths are in meters; animation enlarges the workstation.
No. Rating converts observed to normal time; travel speed is a separate control.
They produce different numerical standards. This lab defines allowance as a fraction of standard time.
Travel distance falls while fixed assembly work remains ten seconds.
Deterministic illustrative motion study, one repeated assembly cycle, constant travel speed, no acceleration or bimanual overlap. Rating and allowance affect reported standards only, not physical hand speed. No certified work standard or ergonomic safety claim. Coordinates and paths are in meters; animation enlarges the workstation.