The plan versus actual chart is one of the most powerful and simple visual process performance metrics. In fact, it’s a sort of Swiss Army knife of charts in that it not only provides insight into process performance but, by the virtue of its comment field, begs and shares information as to when and why there is a variance from plan. Ultimately, it is about problem identification. The chart is often positioned at the pacemaker process or at the output end of a line or cell (which can be the same thing). It goes by a number of different names: production analysis board, day-by-the-hour chart, ahead or beyond chart, production control board, etc. Typically, the discrete time increments reflected on the chart are hourly, but this is not always appropriate depending upon the takt image (pitch) of the process. The plan should reflect the customer demand as communicated by a pre-set schedule or, when the resource is scheduled by downstream pull signals, the actual pulled quantity serves as the plan. In any event, the plan quantities are intended to reflect and accommodate takt time and, when appropriate, afford for standard internal changeover times. The plan versus actual math is extremely simple (the challenge lies in the discipline and problem solving). While there are a number of derivatives, the figure below is a relatively standard design. It contains two alpha “call-outs” by which the math is explained. 
Some considerations:
- Many lean practitioners will add two columns immediately to the right of the cumulative columns. These additional columns represent the delta between the hourly (or pitch) plan versus actual and the delta between the cumulative plan versus actual. For example, within the figure's 9:20 to 10:20 a.m. row, the hourly delta would be -13 and the cumulative delta would be -21. Clearly, this helps the viewer of the chart more quickly identify the delta, but it does require some quick figuring and writing by the person maintaining the chart…and most folks can easily do the math in their head.
- Not all production quantities are equal. This is true in a mixed model environment where the cycle times for the various products, transactions, or services are significantly different. In such a situation, the plan versus actual may have to use common units for both planned and actual outputs.
Related posts: Pitch: Takt Image Math, Plan Vs. Actual – The Swiss Army Knife of Charts
