I have said multiple times that Mixed Model Line Design is a step-by-step methodology for designing the ultimate Value Stream, but I haven’t told you what the steps are. So that’s what I will do in this video. Remember that we’re keeping these videos short, so this will of necessity be a high-level overview. Let’s go through the steps:
INITIAL ASSESSMENT AND MASTER PLAN
The assessment that we typically do is a Value Stream Map of the current state. The VSM won’t be sufficient to design a Value Stream, but it’s a good and quick snapshot of where you are today.
This is a data-driven methodology, so the first step is going to be gathering and documenting the necessary data. There are several different types of information you’ll need to have, which you can find by downloading a free copy of the Mixed Model Line Design Roadmap on this page.
Once we have this data collected, we’re ready to do some calculations. When I ask how many people love math, almost no one raises their hand. But don’t worry, this is very easy math. Here’s what you need to calculate:
- The volume per process.
- The Takt Time per process.
- The Resources per process.
That’s not too bad, right?
If you are doing work sequentially in a process (like an assembly line), and you need more than one person, then you will need to allocate work steps to more than one workstation. We call this Line Balancing or Workstation Definition. This is a very important part of the line design method, and you will be attempting to allocate the work as evenly as possible from one station to the next. There are a number of balancing tools or strategies that you can use to help you to accomplish this. Again, download the Mixed Model Line Design Roadmap to read through the various Line Balancing tools that are available to you.
CONCEPTUAL LINE LAYOUT
Before you fire up your CAD software, create a block layout. We recommend using sticky notes on a board or table. The idea here is to get everyone on your team involved with the design process, not just the CAD developers. Sticky notes are easy to move around and help you see the high-level processes BEFORE adding in all of the fine details.
This is an optional step, but highly recommended if your design is complex, and it will be very expensive to change it after the fact. You may need to get outside help to create a simulation model (based on your conceptual line design) but you can then test multiple scenarios of mix and volume, and you will almost certainly improve your design.
CREATE A CAD DRAWING
This is a big job also, since we’re now talking about all of the fine details. Here’s a tip that will save a lot of headache in the future: get facilities involved in this effort, as well as the Material Flow team.
At the end of this process you will have a detailed design that you can implement. Like if you’re building a house, once you have the detailed construction documents, you still haven’t built anything yet. But remember that the more time spent on the design, the smoother the construction phase will go.
Thanks and in the next and final video, I’ll share with you the three main ways to learn the subject of Mixed Model Line Design.