Learning Curves ---- advanced

Have you ever put together a bicycle? I bet it took a long time to get it done because you had to read the instructions step-by-step, figure out the parts you had, get the right tools, etc.

But, what if you had to assemble two or three bicycles, how much faster would you have done the second and third ones? You know the parts, you know how the parts go together and you have the right tools. By the third one, you don't even have to look at the instructions anymore.

Cost engineers call this a learning curve....everytime you repeat a task you do it for less hours. The ""curve comes from the shape of a graph of the hours/unit for many units --- an average learning curve says that you can reduce the hours by 20% every time you double the repetitions ..... the 2nd is 80% of the first and the fourth is 80% of the second. Some people have been able to drive learning curves for 30 or 40% reduction.

On one project I worked on we had to assemble 93 packing lines. The estimate was for 5700 hours per line which we met on the first line, but at the end of the project, we did the last lines for 1300 hours each ---- same scope, some of the same people (remember, to get a learning curve, you usually need to reduce the crew size or the schedule time.....if the crew size and schedule time stays the same, you won't see any reduction in hours, just easier work)

But, you don't need 93 identical lines to achieve a learning curve ---- just some repeat work.

So, why don't we plan all work so the same people repeat tasks as much as possible. It appears that work is sometimes planned without recognizing the power of Learning Curves. Sometimes the same work gets assigned to two different crews. Sometimes crews get reassigned to different work. It should be a priority that every time there is the same work, then the same crew should do it.