Standard Work Sheet

What this tool does

CM8-285 is a working standard work sheet. Record one row per work element with its manual, machine and walk time; the tool works out each operator's cycle time, sets it against takt, shows the balance across the cell, counts the walking and waiting, and prints a sheet you can post at the cell. It runs inside this single file: no account, no upload, no network request.

What standard work is

Standard work is the current best-known method of doing a job, written down so that everyone does it the same way and so that it can be improved. That last clause is the point: without a written standard every improvement is improving a moving target, and with one a change is measurable — the sheet before, the sheet after. It is not a straitjacket: it describes the work, and it exists to be beaten.

Which leads to the honest point: standard work you did not write with the operators will not be followed. A sheet written in an office and posted at a cell describes a job nobody recognises; it will be ignored within a week, and everybody will know it. Write the elements at the cell, in the operators' own words, and ask them what it gets wrong.

The three elements of standard work

Standard work has exactly three components; a sheet missing any is not standard work.

• Takt time — the beat the customer sets: available production time ÷ customer demand for the same period. With 27,500 seconds of running time and demand of 500 pieces, takt is 55 seconds. It is not a target you choose; it is arithmetic on demand, and it moves when demand moves.
• Work sequence — the order in which one operator performs their elements, cycle after cycle. Not the route the part takes and not a list of duties: the actual repeated sequence, numbered.
• Standard work-in-process — the minimum pieces that must sit in the cell for the sequence to run without stopping.

The parallel-time rule

Each element can carry three times, and they do not all belong to the operator. Manual time is hands on the work; walk time is the operator moving; machine time is the machine running, and while it runs the operator is free.

This is the most common error in a hand-built sheet, and it is easy to make because a spreadsheet will happily total a row: three columns summed produce a cycle time containing every second the machine was running. In the sample cell Operator 2 starts a 22-second weld cycle and walks away; their real cycle is 52 seconds against a takt of 55 — comfortable. Add the weld time and the sheet says 74 seconds, 19 over takt, and you will be told to add an operator you do not need. The error always inflates cycle times and the operator count. One condition is attached — the operator must genuinely be free. Standing watching the machine is waiting; holding a part against a tool while it cycles is manual time. The tool refuses an automatic element carrying manual time, because a busy operator during a machine cycle means two elements, not one. Record machine time anyway: a 70-second cycle against a 55-second takt says the machine is the constraint.

Balancing against takt

The balance chart is what this tool exists to produce: one bar per operator, its height their manual plus walk time, with takt drawn across as a dashed line.

Read the bars above the line first. An operator whose cycle exceeds takt cannot finish inside the customer's beat — not occasionally, every cycle. In the sample, Operator 1 runs 58 seconds against a takt of 55: three seconds a cycle, which over 500 pieces is 1,500 seconds lost every shift.

Then read the bars well below the line, carefully. An under-loaded operator is not a saving. Operator 3 runs 38 seconds against 55, and it is tempting to claim 17 seconds of recovered labour. You have not: the person is still there all shift and the cell still makes one piece per takt. The saving appears only when elements move to the under-loaded operator and the cell fits inside takt with fewer people. Spare seconds spread thinly are worth nothing; concentrated, they are worth an operator — which is what the operators-needed figure counts. Load each operator a little under takt: a cycle at 100 % has no room for a dropped part, so the balance table calls 90 % of takt up to takt "near takt".

Walk and wait — waste you designed in

Walking and waiting are recorded separately because they are not work. Nobody buys the six seconds it takes to cross the aisle; they exist because of where the bench was put and how the sequence was ordered. Give walk time its own element wherever it is a real journey, so it appears as a line you can point at and delete. Waiting is different, and the tool refuses to record it as manual time: record a wait element with the machine's seconds against it and it shows in the walk-and-wait figure without inflating work content. Waiting is the cheapest waste to remove, usually by resequencing.

Standard WIP and why it belongs on the sheet

Standard work-in-process is the minimum stock the sequence needs: the piece in the fixture, the two in the chute, the six in the part-filled carton. Too low and the operator arrives at a station with nothing to work on; too high and inventory hides the problem that caused it. It is part of the method, not the schedule — when the sequence does not work, a piece was usually missing from a place the sheet assumed would be full.

Quality checks in the sequence, not at the end

Mark the elements that are key quality checks. A check inside the sequence, timed like any other element, stops being optional overhead that gets skipped when the cell falls behind, and catches the defect where it was made. An inspection element counts as work, not waste, and its time counts in the cycle: checking is real work with a real cost and belongs in the balance.

Observing properly

• Time the same operator over five to ten consecutive cycles. One cycle says nothing about whether the method is repeatable.
• Use the repeatable time, not the best time. The lowest time you saw is a lucky cycle; a standard built from best times cannot be met, and so is ignored.
• Time elements, not the whole job. "Assemble bracket, 90 seconds" hides the six decisions inside it. Break where you can see it: a part put down, a button pressed.
• Watch the work, not the person, and note the variation: which fixture is stiff, what a new operator gets wrong.

Revising the sheet after every improvement

Move a bench, change a fixture, alter the sequence, and the sheet is wrong from that moment. Reissue it. A sheet updated after every change is a live record of the best-known method; a year-old sheet is wall decoration. The new method becomes the sheet, the sheet becomes the training, and the next improvement starts from there. Takt moves more often than the method does, so re-run the balance whenever demand moves.

The spreadsheet workflow

If the element times already exist in a spreadsheet, you need not retype them.

• Spreadsheet template in the toolbar saves a CSV whose headings are exactly this tool's column names, with a guidance row underneath showing what each expects — the values the element type list accepts, the unit for each number, and which columns are required.
• Fill in one row per work element, delete the guidance row, and keep the file as CSV.
• Import spreadsheet reads it back, matching columns by heading, so their order does not matter and extra columns are ignored. Rows failing a required column or a validation check are skipped and reported by row number.

The file is read in your browser: nothing is uploaded, and importing adds to what is here.

The formulas

The walk-and-wait share is measured against the seconds the operators are tied up — operator cycle plus waiting — not every second on the sheet, because parallel machine time is not theirs to lose. The value-class chart splits every recorded second three ways: manual is work, machine time on running elements is machine, walk and wait are waste.

FAQ

How fine should an element be? Fine enough to move to another operator, coarse enough to time reliably — usually three to forty seconds. A minute-long element almost certainly hides a walk and a wait.

We are under takt but still miss demand. Why? Standard work assumes the sequence runs uninterrupted; breakdowns, changeovers, shortages and rework eat the available time takt came from.

Is the operator count a headcount decision? No. It is arithmetic on the work content at the takt you entered, assuming elements move freely between people. Reach, competence, qualifications, safety and layout all constrain that, and none of them are in this file.

Saving your work

Elements, settings and the report header are written to this browser's local storage as you type, and that storage belongs to one browser on one computer. Treat Export .json as the real save; Import .json restores it anywhere. Reset asks twice, then erases everything.

Accuracy & disclaimer

The arithmetic is simple and the tool does it faithfully. The judgement underneath is yours: whether the elements are the right ones, whether the times are repeatable, whether an operator was really free during a machine cycle, and whether takt reflects genuine available time and genuine demand.

This sheet records times observed for one product, on one layout, at one takt — re-observe and reissue it whenever the product, the layout, the tooling or the demand changes. It is a calculation aid, not a certified standard and not engineering advice; reach, handling and machine guarding must be assessed by whoever is competent for that cell.