Work element breakdown: how to divide a job into elements

Why it matters

Knowing the total cycle time is not enough to understand which part of the work changed. If picking up, placing, securing and inspecting the part stay on one row, the time-consuming section cannot be explained. A work element is a portion of work tracked separately for a defined purpose. Its name describes the work, and its boundary rests on a visible event. Choose the level of detail to suit the question. Every finger movement need not become a separate row; however, hiding human work and automatic operation in the same element makes later calculations harder. The work sequence established in method study gains measurable boundaries here. Before measurement, verify that these definitions can be followed on the shop floor.

The end of one element may be the start of the next on the same resource. Sequential boundaries built this way make it easier to account for the entire cycle. ‘Placement complete’ can mean different things to two observers. ‘The part is seated and the hand leaves it’ is a clearer event. However, a well-written sentence is insufficient if the selected event cannot be seen on camera or in live observation. The boundary must also be observable. Explain which element includes each transition movement; do not leave gaps between elements to chance. Therefore, compare the total cycle and the time covered by its elements separately.

A person and machine can work simultaneously. If the worker's preparation fits inside automatic operation, adding the two durations does not give elapsed time. Human work content, machine running time and cycle time are different quantities. Without stating which quantity is reported, the same work can be counted twice. Separate lanes on a timeline make this distinction visible. Lanes represent resources; horizontal position represents the same real time. Overlapping blocks are simultaneous; consecutive blocks are sequential. With several workers, keep each person's work content separate too. Reassess the simple addition rule when the resource boundary changes.

Some work is not done every cycle. Record both duration and frequency for box changes, regular cleaning or adjustments made after a set number of parts. The average load per part does not change when the work actually occurs. Treating all cycles as equally long can hide flow requirements during the long cycle. Distinguish event-related work from regularly recurring work too. The frequency of regular work is known; the frequency of an unexpected event needs separate observation. Work element breakdown is more than preparing a list. It establishes a measurement structure that preserves the sequence, resource and frequency of durations.

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