Time and Motion Studies

Abstract

Time and motion study is a form of task performance and analysis that measures how a task is actually done and how long each part of it takes. It fuses two originally separate traditions: Frederick Taylor’s stopwatch time study, which sets a standard time for a job, and the Gilbreths’ motion study, which decomposes the work into elemental hand motions and removes the wasteful ones. The paradigm gave industrial psychology the therbligs, predetermined motion time systems, the learning curve, and a measurement vocabulary still in use, and it rests on a cognitive claim: that skilled action is compositional, much of it is waste, and the efficient method can be taught. Once the tool of the factory floor, the method now reappears in the clinic, where observational and electronic-health-record studies quantify how clinicians spend their day.

Keywords: time study, motion study, therblig, standard time, performance rating

Few ideas have shaped the modern workplace as quietly as the proposition that a task can be watched, timed, taken apart, and reassembled in a better order. Time and motion study began as the engineering of manual labour, but its deeper claim is cognitive: that skilled action is built from a small set of reusable elements, that much of what a worker does is unnecessary, and that the right method can be discovered and taught rather than left to habit. That claim connects the method to the psychology of skill learning, attention, and psychomotor performance, and it is why a technique a century old still governs how a hospital, a warehouse, or an assembly line is run.

What Time and Motion Studies Are

A time and motion study is a direct, structured observation of a task that records both its method — the sequence of physical and mental steps a worker performs — and its timing — how long each step takes. The output is twofold: a description of the one best way to do the job, and a number, the standard time, that says how long the job should take when done that way by a trained worker at a sustainable pace.

The discipline sits at the intersection of industrial engineering and psychology. Its engineering side measures and standardises; its psychological side rests on three assumptions about skilled human action. First, that complex manual work is compositional — built from a limited inventory of elemental motions that recur across tasks. Second, that much observed activity is waste — searching, hesitating, repositioning, holding something that a fixture could hold. Third, that the efficient method is learnable and teachable — once discovered, it can be installed in a new worker rather than rediscovered by each one. Lillian Gilbreth made this psychological reading explicit, arguing that the mind of the worker, not merely the motion of the hand, is the proper subject of management (Gilbreth, 1914).

MeSH classifies “Time and Motion Studies” under Task Performance and Analysis, reflecting that the method is, at root, a way of analysing how a task is performed. That placement links it to the broader cognitive literature on how multiple demands, divided attention, and limited working memory shape what a person can actually do within a fixed span of time.

Origins: Taylor’s Time Study and the Gilbreths’ Motion Study

The two halves of the method were invented separately, by rivals. Frederick Winslow Taylor, a mechanical engineer at Midvale and Bethlehem Steel, built time study in the 1880s and 1890s: he timed the elements of a job with a stopwatch, discarded the slow and clumsy versions, and set the fastest sustainable time as the standard every worker was then expected to meet. His Principles of Scientific Management (Taylor, 1911) made this the centrepiece of a management philosophy — that there is one most efficient way to perform any task, discoverable by measurement, and that it is management’s job to find it and the worker’s to execute it.

Frank and Lillian Gilbreth approached the same problem from the opposite direction. Rather than timing a method already in use, they analysed the motions themselves, hunting for the most efficient pattern before timing anything. Frank Gilbreth’s Motion Study (Gilbreth, 1911) used photography and the cyclegraph — a long-exposure photograph of a light fixed to the worker’s hand — to make the path of a motion visible and so to expose its inefficiency. Where Taylor asked how long a method took, the Gilbreths asked what the best method was. The two camps competed openly (Nadworny, 1957), but the techniques were complementary, and the hyphenated phrase time-and-motion study records their eventual fusion into a single discipline.

Figure 1

Therbligs: The Elements of Motion

The Gilbreths’ most durable contribution was an alphabet of motion. In Applied Motion Study (Gilbreth & Gilbreth, 1917) they proposed that every manual operation decomposes into a small fixed set of elemental motions — search, find, select, grasp, transport loaded, position, assemble, use, release, and so on. They called these elements therbligs (“Gilbreth” reversed, roughly), and there are seventeen of them.

The point of the inventory is diagnostic. Therbligs sort into effective motions, which advance the task (transport loaded, grasp, assemble, use, release), and ineffective motions, which do not (search, select, hold, position, unavoidable delay, rest to overcome fatigue). Wasted effort is precisely the time spent in ineffective therbligs, and the aim of motion study is to redesign the workplace — the layout of parts, the fixtures, the sequence — so that ineffective motions shrink or vanish. A part placed within easy reach eliminates a search; a jig that holds the work eliminates a hold. This was the method the Gilbreths later carried into the operating room, analysing the surgeon’s motions exactly as they had the bricklayer’s (Baumgart & Neuhauser, 2009).

Measuring Work: Standard Time and Predetermined Systems

Timing a job is not as simple as reading a stopwatch, because a stopwatch records what one worker did on one occasion, not what a job should take. Two corrections bridge the gap. First, performance rating: the observer judges the pace of the timed worker against a defined normal pace and scales the reading accordingly — a worker timed at 110% of normal has their observed time multiplied by 1.10 to give the normal time. Second, an allowance for personal needs, fatigue, and unavoidable delay is added, because no one can work without pause. The result is the standard time:

standard time = observed time × performance rating × (1 + allowance)

Ralph Barnes’s textbook Motion and Time Study (Barnes, 1980) codified this procedure for generations of industrial engineers, and it remains the canonical stopwatch method.

A more radical idea removes the stopwatch entirely. A predetermined motion time system (PMTS) assigns a fixed, tabulated time to each basic motion — reach, move, grasp, position, release — derived from large prior studies. The most influential is Methods-Time Measurement (Maynard, Stegemerten, & Schwab, 1948), which expresses times in time measurement units (1 TMU = 0.036 second). Because the times are fixed in advance, an engineer can compute a standard time for a job from its motion description before the job is ever performed — invaluable for designing a workstation or costing a product that does not yet exist.

The Learning Curve

A standard time assumes a trained worker, which raises a question the early engineers could not ignore: how does performance improve with practice? The answer, discovered in aircraft manufacturing, is the learning curve. T. P. Wright observed that each time cumulative production doubled, the cumulative average labour per unit fell by a constant percentage (Wright, 1936). An 80% learning curve means that doubling output cuts the cumulative average time to 80% of its previous value: if the first unit takes 10 hours, the average over the first two is 8 hours, over the first four 6.4 hours, and so on.

Formally, the cumulative average time for unit x is Y = a · x^b, where a is the time for the first unit and b = log(learning rate) / log(2) is a negative exponent fixed by the learning rate. The curve is a direct cognitive signature: it is the macroscopic trace of skill acquisition, the same power-law speed-up that governs individual psychomotor performance and reaction time with practice, aggregated across a whole workforce. It is why a standard time set on week one is wrong by week ten, and why work measurement must distinguish the learning phase from the steady state.

Modern Applications: Clinical Workflow and the EHR

The factory gave the method its birth, but medicine has given it a second life. The question — where does the working day actually go? — is the same, but the stakes are now clinician burnout and patient safety rather than piece-rate wages. A methodological review found that “time and motion study” is used loosely in healthcare, spanning continuous observation, work sampling, and self-report, and argued for the rigorous continuous-observation form the Gilbreths would have recognised (Lopetegui et al., 2014).

The landmark modern study timed physicians directly across four specialties and found that for every hour of face-to-face time with patients, nearly two additional hours went to the electronic health record and desk work (Sinsky et al., 2016). Johanna Westbrook’s group developed the observational tooling — software for recording multitasking and interruptions in real time — that made such studies reliable. A parallel approach dispenses with the human observer altogether: the electronic health record logs every click, so its audit trail is itself a time study, measuring EHR time objectively and at scale (Overhage & McCallie, 2020). Related work using the same logs showed physicians splitting their time roughly evenly between patients and “desktop medicine” (Tai-Seale et al., 2017), and observational time-and-motion studies of nursing continue to map how clinical staff spend their shifts (Michel et al., 2021).

Worked Example

Suppose an analyst times a packaging task and records a mean observed cycle time of 0.80 minutes. The worker is judged to be moving briskly, at a performance rating of 110% (1.10), and the plant applies a standard allowance of 15% (0.15) for fatigue and personal needs. The standard time is built in two steps.

First, correct for pace to get the normal time — the time the job would take at exactly normal pace:

normal time = 0.80 × 1.10 = 0.88 minutes

Then add the allowance to get the standard time:

standard time = 0.88 × (1 + 0.15) = 0.88 × 1.15 = 1.012 minutes

So although the stopwatch read 0.80 minutes, the fair production standard is 1.012 minutes per unit. Over a 480-minute shift, the expected output is 480 / 1.012 ≈ 474 units. The direction of each correction matters: rating the brisk worker up to 1.10 makes the normal time longer than the raw reading (0.88 > 0.80), because a slower, normal-paced worker would take longer; the allowance then lengthens it again. Had the worker instead been rated at 90% (sluggish), the normal time would have been 0.80 × 0.90 = 0.72 minutes, and the standard time 0.72 × 1.15 = 0.828 minutes — a reminder that the rating step, the one genuinely subjective judgment in the procedure, moves the final number substantially and is where two analysts are most likely to disagree.

Discussion

The enduring tension in time and motion study is between its mechanical precision and its human subject. The arithmetic of a standard time looks objective, but it rests on the performance rating — a human judgment of another human’s pace — which no amount of decimal places can make exact. Taylor’s assumption of “one best way” is powerful for a fixed, repetitive task but brittle for cognitive or variable work, where the best method depends on the situation and the worker’s own strategy. Lillian Gilbreth’s insistence that fatigue, motivation, and satisfaction belong inside the analysis, not outside it, was the humane correction to Taylor’s austerity, and it anticipated the modern field of human factors.

The two source traditions differ in emphasis, as the table shows.

In practice the two are inseparable: there is no point timing a wasteful method, and no point perfecting a method that cannot be measured. The fused discipline is why a well-run operation first designs the motions, then times them, and only then sets the standard.

Current Directions

The method’s contemporary frontier is automatic, high-resolution, and clinical. The electronic health record audit log has turned the time study from a scarce, observer-limited snapshot into a continuous census of digital work, letting researchers track EHR time for entire health systems rather than a sampled few (Overhage & McCallie, 2020). The open problem is interpretation: a click log records what was done and when, but not the cognitive load, the interruptions, or the multitasking that the Gilbreth-style human observer captured — which is why observational tools for coding interruptions and concurrent activity remain in active development and are still run alongside the logs (Michel et al., 2021). Wearable sensors, computer-vision motion capture, and the analysis of clinical workflow as a measurable determinant of burnout are extending the century-old question — where does the time go, and how much of it is waste? — into settings the Gilbreths never imagined.

Key Researchers

Frank Bunker Gilbreth

(1868–1924). Founded motion study, using photography and the cyclegraph to decompose manual work into elemental motions and (with Lillian Gilbreth) to define the therbligs, the seventeen fundamental motions from which wasted effort can be identified and removed. Wikipedia

Lillian Moller Gilbreth

(1878–1972). One of the first female engineers to hold a PhD and a founder of industrial-organisational psychology; her Psychology of Management (1914) insisted that method study address the worker’s mind, fatigue, and satisfaction, not only mechanical motion. Wikipedia

J. Marc Overhage

(contemporary). Informatics researcher, formerly of the Regenstrief Institute and Indiana University School of Medicine, who pioneered the electronic-health-record log as an objective, large-scale time study, replacing the human observer with the system’s own event trail. ORCID

Christine Sinsky

(contemporary). Vice President for Professional Satisfaction at the American Medical Association, who led the 2016 four-specialty time-and-motion study quantifying how much of the ambulatory physician’s day is spent on the electronic health record and desk work. ORCID

Frederick Winslow Taylor

(1856–1915). Mechanical engineer who founded time study and scientific management; his stopwatch timing of work elements and doctrine of the one most efficient method set the measurement half of the discipline. Wikipedia

Johanna Westbrook

(contemporary). Director of the Centre for Health Systems and Safety Research at Macquarie University, who developed modern observational time-and-motion methodology for healthcare — including tools for recording multitasking and interruptions — and co-authored the 2016 physician time study. ORCID · Faculty · Google Scholar

Glossary

Allowance.

An increment added to the normal time to account for personal needs, fatigue, and unavoidable delay, expressed as a fraction of the normal time.

Cyclegraph.

A long-exposure photograph of a small light attached to the worker’s hand, used by the Gilbreths to make the path of a motion visible for analysis.

Effective motion.

A therblig that advances the task, such as transport loaded, grasp, assemble, use, or release.

Elemental motion.

The smallest meaningful unit of manual work into which a task is decomposed; in Gilbreth analysis, a therblig.

Ineffective motion.

A therblig that does not advance the task, such as search, select, hold, position, or delay; the target of motion-study elimination.

Learning curve.

The empirical relationship by which the cumulative average time per unit falls by a constant percentage each time cumulative output doubles.

Methods-Time Measurement (MTM).

The best-known predetermined motion time system, assigning tabulated times (in time measurement units) to basic motions such as reach, move, grasp, and position.

Motion study.

The Gilbreth half of the discipline: the decomposition of a task into elemental motions in order to find and eliminate wasted movement and establish the best method.

Normal time.

The observed time corrected by the performance rating, representing how long the task would take at a defined normal pace, before allowances.

Performance rating.

The observer’s judgment of the timed worker’s pace relative to a defined normal pace, used as a multiplier on the observed time.

Predetermined motion time system (PMTS).

A method that assigns fixed, tabulated times to basic motions, allowing a standard time to be computed before the job is performed.

Scientific management.

Taylor’s management philosophy built on time study, task standardisation, and the division of planning from execution; also called Taylorism.

Standard time.

The time a trained worker should take to complete a task at normal pace with allowances, computed as observed time × performance rating × (1 + allowance).

Therblig.

One of the seventeen fundamental elemental motions defined by the Gilbreths (the name is roughly “Gilbreth” reversed) into which any manual operation can be analysed.

Time study.

The Taylor half of the discipline: the stopwatch timing of work elements to establish a standard time for a job.

Work sampling.

A statistical alternative to continuous timing in which a task is observed at random intervals and the proportion of observations in each activity estimates the time spent on it.

Frequently Asked Questions

What is the difference between time study and motion study?

Time study, from Frederick Taylor, times the elements of a job with a stopwatch to set a standard time. Motion study, from Frank and Lillian Gilbreth, decomposes the work into elemental hand motions to find and eliminate wasted movement. Time study asks how long the job should take; motion study asks what the best method is. Modern practice fuses them, which is why the combined phrase is “time and motion study.”

What are therbligs?

Therbligs are the seventeen fundamental elemental motions — search, grasp, transport, position, assemble, use, release, and so on — into which the Gilbreths decomposed any manual task. The name is “Gilbreth” spelled roughly backward. Sorting them into effective and ineffective motions is how an analyst locates wasted effort.

How is standard time calculated?

Standard time equals the observed time multiplied by the performance rating and then by one plus the allowance. The performance rating corrects the raw stopwatch reading for how fast or slow the timed worker was moving, and the allowance adds time for fatigue, personal needs, and unavoidable delay.

What is a performance rating?

A performance rating is the observer’s judgment of the timed worker’s pace relative to a defined normal pace, expressed as a percentage. A worker judged to be moving at 110% of normal has their observed time multiplied by 1.10. It is the one genuinely subjective step in the procedure and the main source of disagreement between analysts.

What is a predetermined motion time system?

It is a system, such as Methods-Time Measurement (MTM), that assigns fixed, tabulated times to basic motions derived from prior studies. Because the times are known in advance, an engineer can compute a standard time for a job from its motion description before the job is ever performed, which is useful for designing a new workstation or costing a product.

What is the learning curve in this context?

The learning curve describes how the cumulative average time per unit falls by a constant percentage each time cumulative output doubles. An 80% curve means doubling output cuts the average time to 80% of its prior value. It matters because a standard time set early in production will be too generous once workers have learned the job.

Is time and motion study still used today?

Yes. Beyond manufacturing and logistics, it is widely used in healthcare to measure how clinicians spend their time, both by direct observation and by analysing the electronic health record’s own audit logs. These studies have become central to research on clinician workload and burnout.

What is the criticism of time and motion study?

Critics argue that it treats workers as machines, that its “one best way” ignores individual strategy and situational variation, and that the all-important performance rating is an unavoidably subjective judgment. Lillian Gilbreth’s own work anticipated these objections, insisting that fatigue, motivation, and satisfaction be analysed alongside motion.

References

Barnes, R. M. (1980). Motion and time study: Design and measurement of work (7th ed.). John Wiley & Sons.

Baumgart, A., & Neuhauser, D. (2009). Frank and Lillian Gilbreth: Scientific management in the operating room. Quality & Safety in Health Care, 18(5), 413–415. https://doi.org/10.1136/qshc.2009.032409

Gilbreth, F. B. (1911). Motion study: A method for increasing the efficiency of the workman. D. Van Nostrand.

Gilbreth, F. B., & Gilbreth, L. M. (1917). Applied motion study: A collection of papers on the efficient method to industrial preparedness. Sturgis & Walton.

Gilbreth, L. M. (1914). The psychology of management: The function of the mind in determining, teaching, and installing methods of least waste. Sturgis & Walton.

Lopetegui, M., Yen, P.-Y., Lai, A., Jeffries, J., Embi, P., & Payne, P. (2014). Time motion studies in healthcare: What are we talking about? Journal of Biomedical Informatics, 49, 292–299. https://doi.org/10.1016/j.jbi.2014.02.017

Maynard, H. B., Stegemerten, G. J., & Schwab, J. L. (1948). Methods-time measurement. McGraw-Hill.

Michel, O., Garcia Manjon, A.-J., Pasquier, J., & Ortoleva Bucher, C. (2021). How do nurses spend their time? A time and motion analysis of nursing activities in an internal medicine unit. Journal of Advanced Nursing, 77(11), 4459–4470. https://doi.org/10.1111/jan.14935

Nadworny, M. J. (1957). Frederick Taylor and Frank Gilbreth: Competition in scientific management. Business History Review, 31(1), 23–34. https://doi.org/10.2307/3111727

Overhage, J. M., & McCallie, D., Jr. (2020). Physician time spent using the electronic health record during outpatient encounters: A descriptive study. Annals of Internal Medicine, 172(3), 169–174. https://doi.org/10.7326/M18-3684

Sinsky, C., Colligan, L., Li, L., Prgomet, M., Reynolds, S., Goeders, L., Westbrook, J., Tutty, M., & Blike, G. (2016). Allocation of physician time in ambulatory practice: A time and motion study in 4 specialties. Annals of Internal Medicine, 165(11), 753–760. https://doi.org/10.7326/M16-0961

Tai-Seale, M., Olson, C. W., Li, J., Chan, A. S., Morikawa, C., Durbin, M., Wang, W., & Luft, H. S. (2017). Electronic health record logs indicate that physicians split time evenly between seeing patients and desktop medicine. Health Affairs, 36(4), 655–662. https://doi.org/10.1377/hlthaff.2016.0811

Taylor, F. W. (1911). The principles of scientific management. Harper & Brothers.

Wright, T. P. (1936). Factors affecting the cost of airplanes. Journal of the Aeronautical Sciences, 3(4), 122–128. https://doi.org/10.2514/8.155