High School Math and Lean

Let’s break out a little high school math and talk about a difference between shop floor cycle times and the time it takes to do work in the office.

Cycle time on the shop floor is fairly straightforward. There is a time that a task takes, plus a little more time for every option that is installed.

In the office, though, cycle time often follows the formula Y=mX + b. For those of you with a sharp memory, that’s the formula for a line.

In this case, ‘b’ is the time it takes to do the standard part of the work unit (filling out shipping and payment information on an order, for example). ‘X’ is the number of time drivers, like line items on an order, accounts to validate on a loan application, or images to add to a piece of marketing collateral. The ‘m’ is the time per item. When you calculate this all out, you get a total time for the specific size of the work unit, or your ‘Y’ value.

Having a good understanding of this formula helps keep you from chasing your tail. If there is a lot of variation on the input to a process, there will also be a lot of variation on the output. Sometimes that variation is not a bad thing, as in the case of more lines on an order.  The key is to always be looking at your process to gain a full understanding of what is happening. When you know what is really going on, your continuous improvement efforts will be much more fruitful.