How to Implement Lean Manufacturing: Simplify and Solve – Value Stream Mapping and Team Problem Solving: Part 8
In our last post, I said we’d look at a few more VSM’s and talk about the data on them by way of analysis.
Here’s a quick one.
You’ll notice right away that uptime at several of the operations just stinks. Painting is available only half the time? Really? And those 75% uptimes are problems, too. Poor availability might be the reason for the high WIP and finished goods inventory. High scrap rates might be another reason but, once again, we don’t have scrap data, so it’s hard to tell. We also don’t have data regarding batch sizes, so we don’t know if a process runs on one work order for one hour or one week. That might be nice to know.
Finally, the fact that each process step is scheduled separately has something to do with high inventories. We’ll come back to this in subsequent discussions.
OK, we’ve probably looked at enough current state VSM maps. Here’s a wrapup:
- Gather lots of data that show how the process overall and the steps of the process are performing. Those data should include scrap, cycle time, asset uptime/availability, on time production and delivery, change over time, raw material inventory, WIP, and finished goods inventory.
- As you’re entering data into the VSM, record range of performance as well as average or median performance (I like median better).
- First, look at inventory throughout the process. Everything else being equal (and, yeah, I know…it never is), you should have no more than a month of total inventory (Raw + WIP + Finished) in the flow. Then, look at on time delivery. If you’re below 98%, you’ve got room for improvement. If you’re below 90%, you’re pissing customers off….get to work!
- Then look at the other performance data. Compare your process performance against “best in class”. Look at the range of performance. These analyses will point you to opportunities for improvement.
Next time, we’ll start putting together a future state VSM.