What is Time and Motion Study?
Time and Motion Study is a systematic work measurement technique used to analyse and improve the way work is performed, determine the time a qualified worker needs to complete a task at a defined rate of working, and establish fair, scientifically defensible labour standards. It combines two related but distinct disciplines: Time Study (measuring how long tasks take) and Motion Study (analysing how tasks are performed, to eliminate unnecessary movement).
Time and Motion Study is the systematic observation, recording, and critical analysis of existing and proposed methods of doing work — with the dual objective of establishing the standard time to perform a task at a normal pace and redesigning the work method to eliminate all wasteful, unnecessary, and inefficient movements.
Together, Time and Motion Study forms the foundation of Work Study — the industrial engineering discipline concerned with the examination of human work to find the most efficient method and establish the time required to do it. It is the primary tool for setting labour standards, pricing products, balancing production lines, calculating machine utilisation, designing incentive schemes, and improving productivity without additional capital investment.
In the past the man has been first; in the future the system must be first. The best management is a true science, resting upon clearly defined laws, rules, and principles as a foundation.
— Frederick Winslow Taylor, Principles of Scientific Management, 1911History & Founding Pioneers
Time and Motion Study has a rich intellectual history spanning nearly 150 years — shaped by engineers, scientists, and industrial visionaries whose insights transformed manufacturing productivity worldwide.
Taylor conducted the world's first systematic time studies at Midvale Steel Company in 1881, using a stopwatch to break jobs into elements, time each element, and establish standard times. His 1911 book Principles of Scientific Management formalised the concept and sparked a global productivity revolution. Taylor believed that for every task, there is "one best method" — and time study was the tool to find it.
Frank Gilbreth, a bricklaying contractor, pioneered Motion Study by analysing the movements used in laying bricks — reducing the motions from 18 to 5 and tripling productivity. He and his wife Lillian (a psychologist) invented the Therblig system — 18 fundamental hand motions — and pioneered the use of film (Micromotion Study) to capture and analyse movement. Lillian's psychological perspective added fatigue and worker wellbeing to the discipline.
Maynard and his team developed Methods-Time Measurement (MTM) in 1948 — a predetermined motion time system that assigns standard times to fundamental human motions without the need for a stopwatch. This allowed time standards to be set for jobs that did not yet exist. The MOST (Maynard Operation Sequence Technique) system followed, further simplifying application for industrial practitioners.
Modern Time and Motion Study uses video recording software with frame-accurate timestamping, wearable motion sensors, and AI-powered activity classification to eliminate observer bias and dramatically speed up analysis. What once took weeks of stopwatch study can now be captured, classified, and standardised in hours — with far greater accuracy and traceability.
Time Study vs Motion Study
Though often used together under the umbrella of "Time and Motion Study," these two disciplines have distinct objectives, methods, and outputs. Understanding the difference is essential for applying the right technique to the right problem.
Focuses on how long a task takes. Uses a stopwatch (or video) to time every element of a job, rates the worker's pace against a defined normal, adds allowances for personal needs and fatigue, and calculates the Standard Time — the time a qualified worker should take to complete the task at a sustainable pace.
Output: Standard Time (minutes per unit) used for scheduling, costing, line balancing, and incentive setting.
Focuses on how a task is performed. Analyses every physical movement made by the worker — using observation, film, or sensors — to identify and eliminate unnecessary, inefficient, or fatiguing motions. Redesigns the work method, workstation layout, tooling, and sequence to minimise motion and effort.
Output: Optimised Work Method — fewer motions, less fatigue, reduced cycle time, improved ergonomics.
The two are complementary and sequential: Motion Study should always precede Time Study — you should first optimise the method (motion study), then measure the optimised method (time study). Measuring a wasteful method and setting standards based on it locks inefficiency into the system permanently.
The Time Study Process — Step by Step
A rigorous Time Study follows a defined sequence of steps. Skipping or short-cutting any step introduces error into the standard time — with lasting consequences for labour costs, scheduling, and operator morale.
Define clearly which job or operation is being studied. Select a qualified, experienced operator who is working at a normal, sustainable pace under normal working conditions. Do not select the fastest or slowest worker — a worker who represents the typical competent performance. Brief the operator on the purpose of the study and obtain their cooperation. Industrial relations and trust are critical to study validity.
Before timing begins, document the current work method completely: the sequence of operations, tools and materials used, workstation layout, and any relevant quality standards. Create an Operation Process Chart or Flow Process Chart. This documentation ensures the study is tied to a specific method — so if the method changes later, the standard must be re-studied.
Break the job into elements — the smallest logical, measurable subdivisions of the operation. Each element should be: (1) clearly defined with an unambiguous start and end point (breakpoint), (2) short enough to be timed accurately but long enough to measure consistently (typically 0.04 minutes or above), and (3) separate from adjacent elements that have different natures (e.g., machine-controlled vs operator-controlled).
Separating machine time from operator time is especially important — machines always run at 100% performance rating, while operators must be rated subjectively. Mixing them produces incorrect standards.
Using a calibrated stopwatch (or video recording), time each element across a minimum of 30 consecutive cycles to obtain a statistically reliable sample. Two timing methods are used: Continuous Timing — the watch runs continuously and elemental times are calculated by subtraction at each breakpoint; and Flyback (Snapback) Timing — the watch is reset to zero at each breakpoint. Continuous timing is generally preferred as it captures all time and prevents observer bias.
Record the actual observed time (OT) for each element in each cycle. Identify and note any foreign elements — activities outside the defined job that occur during the study — and exclude them from calculation.
The Basic Time is the time a task would take if performed at the defined standard (normal) pace — Rating 100 on the BSI scale. It is calculated for each element as:
Basic Time = Observed Time × (Rating / 100)
The average of all valid observed times for each element is first calculated, then multiplied by the average rating given to that element. The sum of Basic Times for all elements gives the Total Basic Time for one cycle of the job.
Performance Rating — The Most Critical Skill
Performance Rating is the process by which the time study analyst assesses the speed and effectiveness of the worker's performance relative to a defined concept of normal working — and expresses it as a percentage. It is the most subjective and most critical skill in the entire time study process. An incorrectly applied rating invalidates all subsequent calculations.
The most widely used rating scale is the BSI 0–100 Scale, where 100 = Normal Pace — the speed at which a motivated, qualified worker can comfortably sustain output over an 8-hour shift without undue fatigue. The BSI 0–100 scale corresponds to the pace of walking 4.8 kilometres per hour on the level.
| BSI Rating | Description | Analogy | Category |
|---|---|---|---|
| 0–49 | Extremely slow — clearly not motivated or very inexperienced | Aimless walking, no purpose | Unacceptable |
| 50–74 | Slow — deliberate, careful but below normal | Casual walking 3.2 km/h | Below Normal |
| 75–99 | Approaching normal — attentive but slightly hesitant | Brisk walking 4 km/h | Near Normal |
| 100 | Normal — steady, effective, qualified worker | Walking 4.8 km/h on level | Normal (Standard) |
| 100–124 | Good — alert, skilled, higher than normal effort | Brisk purposeful pace 5.6 km/h | Above Normal |
| 125+ | Excellent — very high effort, exceptional skill | Jogging 6.4+ km/h | Exceptional |
Rating is always applied to operator-controlled elements only — never to machine-controlled time (which always runs at the machine's set speed, regardless of operator). Analysts develop rating skill through systematic practice using calibrated training films and exercises — it is never applied intuitively without training.
Allowances & the Standard Time Formula
No worker can maintain continuous productive output for an entire shift without breaks for personal needs, rest, and unavoidable delays. Allowances are additions to the Basic Time that account for these legitimate, necessary interruptions — converting Basic Time into the Standard Time that can actually be achieved in a real working day.
Time for personal needs — toilet breaks, drinking water, and other personal activities. Typically 5% of total working time as a minimum allowance for all workers regardless of job type.
Additional recovery time based on the physical and mental demands of the job. Varies by posture, force required, environmental conditions (heat, noise), mental concentration, and monotony. ILO tables provide standardised fatigue factors.
Time for minor unavoidable delays not already covered — tool adjustments, brief machine stoppages, minor material issues. Based on observed frequency of interruptions during the study or agreed by negotiation.
Motion Study & Therbligs
Motion Study analyses the how of work — breaking every task into its most fundamental physical components and eliminating every motion that does not add value. Gilbreth's genius was to recognise that all human work can be decomposed into a small number of fundamental hand motions, which he named Therbligs (an anagram of his name).
The eyes or hands grope or search for an object. One of the most wasteful Therbligs — eliminate by standardising tool locations with 5S and shadow boards.
Choosing one item from a group. Reduce by using colour coding, bin dividers, and dedicated part presentation to make selection immediate and error-free.
Gaining control of an object with the hand. Improve by presenting parts in the correct orientation for a natural, immediate grasp — no repositioning needed.
Moving an object to a destination. Minimise by placing materials within the operator's reach zone — eliminating unnecessary arm extension and walking.
Locating an object in the correct orientation for assembly. Reduce with chamfers, locating pins, and self-aligning fixtures that eliminate manual positioning.
Joining two or more objects. Value-adding — keep, but optimise through fixture design that allows one-handed assembly and consistent part presentation.
Applying a tool or instrument as intended. Value-adding — optimise tool design and ergonomics to reduce effort and maximise speed of use.
Letting go of an object. Minimise by designing "drop-in" disposal — the part should release naturally as the hand moves to the next grasp.
Waiting caused by factors outside operator control. Analyse root causes — machine cycle time, synchronisation issues — and redesign to fill the delay productively.
Waiting under the operator's control — idling, resting outside planned allowances. Pure waste. Address through method improvement and balanced workloads.
Mental delay while deciding on the next action. Reduce by providing clear visual SOPs, pre-sorted materials, and standardised sequences that eliminate decision-making in the cycle.
Deliberate rest due to fatigue. Address through ergonomic workstation design, job rotation, and appropriate fatigue allowances in the standard time.
The Principles of Motion Economy — developed from Gilbreth's Therblig analysis — provide 22 guidelines for designing efficient work methods. Key principles include: use both hands simultaneously in opposite, symmetrical motions; minimise the distance of movements; keep materials within the normal work area (forearm radius); use the lowest-grade muscle group capable of doing the job; and use gravity wherever possible for material handling.
Modern Work Measurement Techniques
Beyond the classic stopwatch time study, several advanced work measurement systems offer faster application, greater consistency, and the ability to set standards before a job physically exists.
MTM (Methods-Time Measurement) and MOST assign standard times to fundamental motions from published data tables — no stopwatch required. Ideal for new products, disputed standards, and ergonomic analysis before production starts.
Takes random snap observations throughout the day to determine the proportion of time spent on different activities. Lower accuracy than time study but requires far fewer resources — ideal for indirect, non-repetitive work like maintenance and office tasks.
Recording work on video and analysing frame by frame. Eliminates observer effect, allows replay for disputed ratings, and enables simultaneous multi-element timing impossible with a single observer and stopwatch.
IMU sensors, smart gloves, and motion capture suits automatically record every movement, force applied, posture, and reach distance — enabling automated Therblig classification and ergonomic risk scoring without manual observation.
Computer vision and machine learning algorithms automatically identify and classify work elements from video footage — generating time studies at a fraction of the cost and time of manual analysis, with consistent, bias-free classification.
Tablet and cloud-based time study applications with electronic data capture, automatic statistical calculations, built-in rating scales, and direct export to ERP/MES systems — replacing paper forms and manual spreadsheet calculations entirely.
Applications & Industry Uses
Time and Motion Study produces outputs that drive decisions across the entire manufacturing and business enterprise. Its outputs are foundational to production planning, costing, and continuous improvement.
Takt time calculation, assembly line balancing, and operator standard work sheets all depend on accurate time studies — conducted for every element of every station on every vehicle line.
SAM (Standard Allowed Minutes) per garment is derived from time study and used to set operator targets, calculate production capacity, and determine piece-rate incentives in every sewing factory globally.
Standard times feed production scheduling, machine loading, capacity planning, and make-or-buy decisions. Without accurate standards, all production planning is guesswork.
Cleanroom and GMP environments require validated standard times for batch release calculations, operator scheduling, and staffing models — where non-conformance carries regulatory consequences.
Time studies of clinical procedures, patient care pathways, and administrative processes enable staffing optimisation, patient safety improvements, and evidence-based resource allocation.
Pick-and-pack time standards, dock-to-stock cycle times, and route optimisation all use time and motion data to set labour budgets and manage throughput in fulfilment centres.
- Establishes fair, defensible labour standards
- Identifies and eliminates wasteful motions
- Enables accurate production capacity planning
- Provides basis for product cost calculation
- Improves workstation ergonomics and reduces fatigue
- Supports line balancing and bottleneck identification
- Provides data for incentive and bonus scheme design
- Exposes method differences between operators/shifts
- Worker resistance — fear standards will be used punitively
- Operator behaviour changes under observation ("Hawthorne Effect")
- Rating subjectivity — different analysts give different ratings
- Standards become outdated when methods or tooling change
- Requires skilled, trained analysts to produce valid results
- Difficult to apply to highly variable or creative tasks
- Industrial relations sensitivity in unionised environments
Summary
Time and Motion Study is one of industrial engineering's most enduring and powerful disciplines. From Taylor's first stopwatch study at Midvale Steel in 1881 to today's AI-powered video analysis and wearable motion capture, its core purpose has never changed: to understand work so precisely that it can be performed better, faster, and with less human effort — while being fair to the workers who perform it.
Key Takeaway
Mastering Time and Motion Study means accepting two truths simultaneously. First: you cannot manage or improve what you have not measured — standard times built on rigorous observation are the foundation of every meaningful productivity metric from OEE to labour cost. Second: measurement alone is not the goal — improvement is. The Motion Study that eliminates unnecessary Therbligs, the method redesign that halves a cycle, the ergonomic improvement that prevents a repetitive strain injury — these are the true outputs of a Time and Motion Study programme. Done with integrity, respect for workers, and genuine commitment to method improvement, Time and Motion Study remains the most powerful and direct path from observation to productivity in manufacturing and beyond.
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