Standard Work Combination Table

A standard work combination table is the most detailed instrument inside the standardized work toolkit. Where the standardized work chart shows the layout and sequence at a glance and the analysis sheet does the math, the combination table puts the operator's cycle on a stopwatch grid and shows exactly how manual time, walk time, and machine time fit together within takt. The diagnostic value is in the overlap. Manual work that has to happen while a machine is idle is wasted overlap, and the table makes it visible by drawing the three categories on the same chart so the team can see the dead air.

"The cycle is not three separate stopwatches. It is one chart with the three colors interleaved. The interleaving is where the throughput lives."

How a standard work combination table works

A combination table is a grid with time on the X axis (usually in seconds) and work elements as rows. Three visual conventions distinguish the categories of time:

• Manual time (often a solid bar) is when the operator is working hands-on at an element.
• Walk time (often a dotted or wavy line) is when the operator is moving between locations.
• Machine time (often a hollow or striped bar) is when the machine is running and the operator could be doing something else.

Takt time is drawn as a vertical line on the chart. The operator's loaded time has to fit within takt, with a small safety margin. The chart is built element by element, with each row showing one work element across its duration in the appropriate color. The team can read down the chart and see exactly what is happening at every second of the cycle.

The diagnostic value lies in the overlap between manual and machine time. If the machine runs for 60 seconds and the operator stands waiting during that window, the chart shows it as dead air. The improvement opportunity is to load manual work into that machine-running window, whether by adding an inspection step, an in-cycle deburr, a pre-stage of the next part, or a walk to a complementary station.

The combination table is built with the operator who runs the cycle. The data comes from a real time study. Built without the operator or from estimates, the chart looks authoritative and quietly inaccurate.

Where a standard work combination table fits on the shop floor of a small manufacturer

Imagine a 22-person precision CNC shop running a high-volume part with an 85-second takt. The operator currently loads the machine, watches the 50-second machine cycle, unloads, walks to inspection, returns, and reloads. Total loaded time is about 28 seconds. The remaining time, especially the 50 seconds of machine cycle, is spent watching.

The shift lead and the operator build a combination table together. They use time-study data to mark manual load at 11 seconds, machine cycle at 50 seconds, manual unload at 9 seconds, walk to inspection at 4 seconds, inspection at 6 seconds, walk back at 4 seconds. The chart shows 30 seconds of overlap available during machine cycle.

The team uses the overlap to move two activities into the cycle. The operator now starts inspection of the previous part during the machine cycle of the next, and pre-stages the next blank during the same window. Loaded time rises from 28 to about 60 seconds, all within the 85-second takt. The shop adds a small fixture for the inspection step at the machine so the operator does not have to walk. Throughput on the part rises 18 percent without a second operator or a second machine.

That is a combination table at small scale. A piece of grid paper, real time-study data, and an overlap that was invisible until the chart drew it.

Common mistakes with standard work combination tables

• Built from estimates. The chart looks right and is wrong. Use a real time study.
• Machine time omitted. Without the third category, the overlap opportunity is invisible. Always include machine time even if it is long.
• Static document. Combination tables shift as elements change, takt moves, and operators find better sequencing. Update them with the standardized work.
• No operator involvement. The combination table without the operator who runs the cycle is fiction. They have to be in the room.
• Treating it in isolation. The combination table is part of standardized work, not a freestanding document. It supports the other artifacts and is updated together with them.

Standard work combination table and related Lean tools

A standard work combination table is one of the three documents that make up standardized work, alongside the standardized work chart and the analysis sheet. It is closely related to standard work more broadly. The time data that populates the chart comes from a time study. When comparing total work across multiple operators against takt, the same time data is plotted as a yamazumi chart.