Time and motion study is one of the oldest disciplines in industrial engineering, dating back over a century, and it remains one of the most reliable ways to find real, quantifiable waste on a production line. For engineers who haven't run one recently, here is a practical grounding in what it actually involves and how to get useful results from it.

What a Time and Motion Study Actually Measures

At its core, a time and motion study breaks down a task into its component actions and measures how long each takes, typically classifying each moment into categories such as:

  • Value-adding work — the part of the process the customer is actually paying for
  • Necessary but non-value-adding time — required movement or setup that doesn't directly add value but can't be eliminated
  • Waste — waiting, unnecessary movement, rework, and idle time that could theoretically be removed

The goal isn't just to produce a number — it's to produce a breakdown specific enough that an engineer can point at a concrete step and say "this fifteen seconds of walking between stations is avoidable."

Common Pitfalls When Running a Study

  • The observer effect. Workers behave differently when they know they're being timed, often working faster or more carefully than normal. Longer observation windows and less intrusive recording methods reduce this effect.
  • Small sample sizes. A single observed cycle rarely represents the true average — variation between operators, shifts, and part variants needs to be captured, not just one "typical" run.
  • Studying the wrong stations. It's tempting to study the station that seems slowest by intuition, but a proper value-stream view often reveals the real bottleneck is somewhere less obvious.
  • Treating the study as a one-time event. Processes drift — part mixes change, tooling wears, operators develop new habits. A study run once a year captures a single snapshot, not the ongoing reality.

Making the Output Useful

A time and motion study is only as valuable as what happens after the data is collected. The most useful studies translate directly into:

  • A specific, prioritised list of waste-reduction actions, not just a percentage figure
  • Updated standard work instructions reflecting the actual best-known method
  • A baseline that can be compared against after changes are implemented, to confirm the change actually helped

Why These Studies Are Run Less Often Than They Should Be

Historically, the biggest barrier to running time and motion studies more frequently has simply been the labour cost of doing them manually — a thorough study on even a single workstation can take a trained engineer one to three weeks of concentrated analysis. That cost forces most facilities to ration studies, running them once a year on a handful of critical lines rather than continuously across the whole facility. Whatever method a team uses to run these studies, the fundamental value of the discipline — quantified, specific insight into where time actually goes — hasn't changed since it was first developed, and it remains one of the highest-leverage exercises an industrial engineering team can run.