Time and Motion Study: Taylor and Gilbreth's Method Explained

By Linh Ngo · Updated Oct 10, 2026

A time and motion study is a pair of work-measurement techniques. Time study uses a stopwatch to record how long each element of a job takes at a normal pace, then adds allowances to set a standard time. Motion study breaks the job into individual movements to remove the ones that add nothing. Together they answer how long a job should take and how it should be done.

What Is a Time and Motion Study?

The phrase glues together two ideas that started with two different people.

Time study comes from Frederick Winslow Taylor. By his own account in The Principles of Scientific Management, he came into the machine shop of the Midvale Steel Company in 1878, and the method he built there was to study the exact series of elementary operations skilled workers used, then time each one with a stopwatch. The study, he wrote, could be made by someone "equipped merely with a stop-watch and a properly ruled notebook."

Motion study comes mainly from Frank and Lillian Gilbreth. Instead of asking how long a worker takes, they asked how many movements the job needs and which of them could go. Purdue's industrial engineering department credits the couple with creating therbligs, the symbols for elemental motions such as grasping or holding. Lillian coined the word, and it's (almost) her surname spelled backwards.

ASME's biography of Frank Gilbreth sums up the difference neatly: the Gilbreths focused on reducing motions, while Taylor's stopwatch approach focused on process times. Most modern work-measurement practice uses both, usually in that order. First fix the method with motion study. Then time the improved method so the standard isn't built around waste.

This article covers where each technique came from, the arithmetic behind a standard time, a step-by-step way to run a study, a template you can copy, and the ethical problems that made stopwatches one of the most argued-over tools in management history. If you want the wider movement they belong to, start with scientific management.

Time Study vs Motion Study vs Related Tools

People often use these terms as if they were interchangeable. They aren't.

Notice that time study feeds the others. You can't balance a line, size a team or set a takt time target honestly without credible task times.

Taylor's Time Study

Taylor's reasoning was simple, and in its day radical. Before him, workers set their own pace and managers guessed. In the Principles, he describes workmen at Midvale who set the pace themselves, limited to about one-third of a good day's work. His fix was to find out what a day's work actually was by measuring it.

The pig-iron example

His most famous case is pig-iron handling at Bethlehem Steel. In Taylor's own text, a gang loading pig iron averaged about 12 and a half long tons per man per day. After studying the work, he concluded that a first-class handler ought to move between 47 and 48 long tons a day. He reported that only about one man in eight in the gang was physically capable of that pace, and that the worker he selected, called Schmidt, averaged a little more than $1.85 a day against the earlier $1.15.

Read that carefully, because it shows both the method and its biggest flaw. The method is to break work into pieces, time the pieces, and allow for rest. Taylor's text records that a first-class pig-iron handler could be under load only 42 per cent of the day. The flaw is the target. He built a standard around a hand-picked, physically exceptional worker, then applied it to everyone else.

Taylor used the same logic on shoveling. He had observers make thousands of stopwatch observations to see how quickly a laborer could push a shovel into a pile and swing a load, and he concluded the best load for a first-class man was about 21 pounds.

Rest is part of the method

People remember Taylor as the man who hurried workers. He also wrote about fatigue. In his bicycle-ball inspection example, he observed that the workers began to get nervous after about an hour and a half of consecutive work. The response was a ten-minute recreation period at the end of each hour and a quarter. He treated rest as something you could calculate and schedule, not something you granted as a favor.

That idea survives in every modern time study as the allowance.

The Gilbreths' Motion Study

Frank Gilbreth started as a bricklayer. ASME's profile says he noticed that workers used different methods, then analyzed their motions to find the best one. He and Lillian developed micromotion study together, a method of recording a task and studying each movement.

Bricklaying, 18 motions down to 5

Taylor cited the result in his own book. In the Principles he wrote that Gilbreth reduced a bricklayer's movements from eighteen motions per brick to five, and in one case to two. Output, per Taylor's account, rose from 120 bricks per man per hour to 350. ASME's biography gives the reduction as 18 motions to 4½. The two sources differ by half a motion, so treat the exact figure as "about five" and the lesson as the point: the old method wasted most of its movements.

The Gilbreths' fix wasn't speed. It was an adjustable scaffold and a better arrangement of the bricks so the bricklayer stopped stooping. Taylor noted that a bricklayer was lowering his roughly 150-pound body two feet about one thousand times a day. Remove the stooping and the effort disappears.

Therbligs and film

The Gilbreths broke every manual job into a small vocabulary of motions. Purdue's page describes a therblig as a symbol representing an elemental motion, such as grasping or holding, and counts 18 recognized ones. You'll see 17 and 18 in different textbooks, so don't be thrown if a source disagrees.

Analysts usually split them into two groups:

• Value-adding motions: reach, grasp, move, position, assemble, use
• Non-value-adding motions: search, select, hold, plan, unavoidable and avoidable delay, rest to recover

The aim is to cut or shorten the second group. That is the logic behind muda, mura and muri in lean thinking: wasted motion is waste, and strained motion is overburden.

The Gilbreths also pioneered motion pictures to study work. ASME records that they used film to study work and workers. Film lets you slow down an operation, count motions and show the worker what you saw.

How Standard Time Is Calculated

Back to the stopwatch. A time study turns raw readings into a standard in four moves.

1. Observed time. The representative stopwatch time for each element of the job.
2. Performance rating. You judge whether the worker moved faster or slower than a normal pace and adjust.
3. Normal time. Observed time multiplied by the rating factor. NPTEL's industrial engineering course writes it as normal time = observed time x rating factor.
4. Standard time. Normal time plus allowances for personal needs, fatigue and unavoidable delays.

NPTEL defines normal performance as the working rate of an average qualified worker under capable supervision, a steady pace that can be sustained day after day without undue physical or mental fatigue. A rating of 100% means exactly that pace. The next lecture in the same course lists several rating systems, including pace rating and the Westinghouse system, which scores skill, effort, conditions and consistency.

For allowances, that lecture gives typical examples: about 4% of normal time as a basic fatigue allowance for light seated work in good conditions, and about 5% for personal needs. These are illustrations, not universal constants. Heavier, hotter or more repetitive work needs more.

A worked example

Say you time how long it takes to pack and label an order. The mean observed time across your cycles is 4.0 minutes. The worker looked a bit quick, and you rate the pace at 110%.

• Normal time = 4.0 x 1.10 = 4.4 minutes
• Allowance of 15% (personal, fatigue and small delays) applied to normal time
• Standard time = 4.4 x (1 + 0.15) = 5.06 minutes

That means a typical qualified worker, working at a sustainable pace and taking normal breaks, should pack about 11 or 12 orders an hour, not the 15 the fast worker managed in the video. (Check your own organization's convention for whether allowances are a percentage of normal time or of total time. The two differ slightly, and you should pick one and state it on every sheet.)

The rating step is the weak link. It rests on human judgment, which is why trained raters, shared benchmark videos and written rating guides matter. Two analysts watching the same operator can easily rate 100% and 115%. Wherever possible, time several workers rather than one.

How to Run a Time and Motion Study, Step by Step

Here's a practical sequence that mirrors the classic ten-step approach in the NPTEL notes, updated for a modern workplace.

1. Define the objective. Are you setting a staffing standard, pricing a service, balancing a line or fixing an injury hazard? The objective decides how precise you need to be.
2. Fix the method first. Don't time a messy process. If the method is unstable, run a quick motion study or draw a spaghetti diagram and tidy it up. Timing a bad method just standardizes the waste.
3. Tell the people involved, early. Explain what you're measuring, why, who will see the data and what it won't be used for. Ask the team to help pick which worker or workers to observe.
4. Break the job into elements. Each element should have a clear start and stop point, such as "pick up form" or "scan barcode." Aim for short elements, but not so short you can't time them reliably.
5. Record method details. Note the operator, equipment, product, layout and conditions on the sheet. Standards without context become impossible to defend later.
6. Time a handful of cycles, then work out how many you need. Variable jobs need more observations than steady ones.
7. Rate the pace at the same moment you time it. Don't rate afterwards from memory.
8. Calculate normal time per element and sum them. Use the rating factor for each element, not one rating for the whole task.
9. Add allowances. Personal, fatigue, delay and any special allowances such as a training allowance.
10. Share the draft standard and test it. Ask the workers whether it's realistic. Revise before it's published, then fold it into your standard operating procedure or standard work document.

A ready-to-copy observation sheet

Copy this table into a spreadsheet and fill one row per element per cycle.

Add a header block with the date, operator initials (or a code if your policy requires anonymity), method version, equipment and the name of the analyst.

Time and Motion Study Examples by Function

The method started on factory floors, but the logic travels. Where it doesn't fit, say so.

The last row matters. Time study works when work is repeatable and cycles are short. When every task is different, a stopwatch will give you a number that looks precise and means nothing.

Criticisms, and Why They Still Matter

Time study has been controversial since the beginning, and some of the criticism is fair.

Worker resistance. In 1911, civilian workers at the Army's Watertown Arsenal went on strike against the arrival of management engineers who used stopwatches to time their work, according to the Massachusetts Historical Society. Congress then banned certain Taylorist methods in military and other federal workplaces. A stopwatch in the hands of someone who can change your pay or your job is a threat, whatever the analyst intends.

Deskilling. Critics argue that breaking a craft into timed elements moves knowledge from the worker to the planner, leaving people with narrow, repetitive tasks and little say over how they work. The risk is real whenever the study's only output is a faster, narrower job.

Unrepresentative targets. The pig-iron example is the textbook case: a standard drawn from a worker who was one in eight is a standard most workers can't meet without harm.

False precision. A standard time of 5.06 minutes sounds exact. It's an estimate built on a sample, a rating judgment and an allowance percentage.

Running one ethically

You can avoid most of these problems with a few commitments you write down before the first reading:

• Say what the study is for, and what it won't be used for. If the answer is discipline or individual ranking, don't run it.
• Invite the workers to choose the observed sample, review the elements and challenge the rating.
• Time a method that has been improved, not the one everyone already knows is broken.
• Build in real allowances for personal needs, fatigue, and delays that aren't the worker's fault.
• Use the standard to plan capacity and find problems in the system, not to rank individuals.
• Share the data and the final standard with the people who do the work.
• Retire standards when methods, tools or volumes change.

If a study can't survive those rules, the study is the problem.

Where Time and Motion Study Lives On

Few teams today carry a Taylor-style clipboard, but the ideas run through lean practice.

• Standardized work. The Lean Enterprise Institute defines standardized work as establishing precise procedures for each operator's work, built on takt time, the work sequence within takt time, and the standard inventory. Once posted at the workstation, it becomes the target of continuous improvement through kaizen. The big difference from Taylor is who owns the standard: the people doing the work are expected to improve it.
• Work elements. The Lean Enterprise Institute describes a work element as a distinct step in one workstation cycle and the smallest unit that can move to another operator. Splitting work into elements exposes hidden waste. That is the Gilbreth idea in lean vocabulary.
• Changeover work. SMED applies motion thinking to machine setup: separate what has to happen while the machine is stopped from what can happen beforehand, then shorten both.
• Line balancing. Element times are the raw material of line balancing, which assigns work to stations so no one is overloaded and no one waits.

The modern pattern is closer to Gilbreth than to Taylor: use video, ask the workers, remove waste, then write the standard down.

Do's and Don'ts

Key Facts

• Taylor's stopwatch method originated in his work at Midvale Steel, which he joined in 1878, and is described in The Principles of Scientific Management.
• Taylor reported that a pig-iron gang averaged about 12 and a half long tons per man per day, against the 47 to 48 tons he concluded a first-class handler should move.
• In Taylor's own account of Gilbreth's bricklaying work, motions per brick fell from eighteen to five, and output rose from 120 to 350 bricks per man per hour. ASME gives the motion reduction as 18 to 4½.
• The therblig is the Gilbreths' unit of elemental motion. Lillian Gilbreth coined the term, and Purdue counts 18 recognized therbligs.
• Normal time equals observed time multiplied by a rating factor. Standard time is normal time plus allowances.
• The 1911 Watertown Arsenal strike was a protest against stopwatch timing and led Congress to ban certain Taylorist methods in federal workplaces.
• Lean standardized work keeps the idea of a documented best-known method, but makes it the object of continuous improvement by the people doing the work.

What to Do Next

Pick one short, repeatable task that bothers people, and run the lightest possible version of this. Film it, count the motions, draw the path on a floor plan, and ask the team what they'd remove. Only then time the improved method. If you find that the real constraint is the layout or the hand-offs, start with the spaghetti diagram. If the work has to flow at a customer-driven pace, move on to takt time.