Optimizing Factory Layout

A scale drawing and a pencil will help you understand and organize the workflow in your plant. November 10, 2005

I'm looking for software to optimize the layout of my factory.

Forum Responses
(Business and Management Forum)
You want to do a search on Lean Manufacturing. Look for a topic called VSM: Value Stream Mapping. This is an exercise where you start with a scale drawing of your building. You arrange your machinery on this layout, then trace the work steps to complete a project. If you start with raw lumber, put your pencil down at the lumber zone. As you drag the pencil around the shop, from station to station, you will soon see something that resembles a plate of spaghetti. This is the current trajectory your project takes.

Your challenge now is to unravel this meandering path and try to make things as concise as possible. A lot of times, the only justification for large batch sizes is the simple fact that it takes a large quantity of parts to amortize the hike from point A to point B. If the distances between these stations is closer, you might be able to delete a couple of carts that you use to store parts that won't be needed for a while. Not only do you not have to have the cart, you don't need to have a place to park the cart. Since you don't need a place to park the cart, you now have a place to put a new machine. And you can then do the same amount of work in a smaller building, or... more work in the same building. The only software necessary is a pencil.

To improve the flow in my factory, I drew up a flow chart. I got myself a fairly large poster board sheet and drew in the plant and machinery (scale) and, using pencil first (later, 5 ink colors), drew in the directions parts and process were going physically through the plant. I found quite a web of parts flowing in several directions (lines going everywhere!), leaving the rough cut operations heading towards shapers, saws, tenonors, rough assembly, and on and on. Some parts were going the length of the plant during stages of process, then returning all the way back to their beginning areas for a final process before once again traveling the full length of the plant to be final sanded and then transferred into the finishing department.

I may not be doing a good job of explaining what the completed chart showed me (and the process of creating it, which took a few days), but it lead to moving a couple machines around and eliminating two employees and dropping out a product which was simply never going to flow well for us.

Another thing we learned with this was that there were employees with time to do more. An example is a person taking the out feed on a shape/sand double end machine. The parts were traveling through approximately 2.5 feet apart and the chain was moving rather slow for good shaping and sanding. So the person taking the outfeed took a part off, stacked it, then waited for the next part to appear. We noticed they had around 5-6 seconds between parts - just long enough to turn to their side and feed in and take out drawer fronts as processed with the Tyler auto dovetail machine. The employee was now doing two jobs with their time, and liked it better, since standing there waiting for those parts was boring and made the day go slow. Now they were keeping busy, doing what we were paying two people to do, and feeling better about their job.

Also, moving the machine (the Tyler) up next to the shape/sand opened up a lot of space, eliminated an employee cost, eliminated the need to link with roller table, and sped up the process.

This may or may not be similar to your business. We were into mass production, where custom is entirely different. But the point is, the chart will show you the complex flows, doing it will bring you close to your operations, and observation of the worker can reveal time for multi-tasking.

Layout varies due to type of product, type of machinery being used and physical structure. Since there is no standard, I suggest software will be limited other than creating a study of flow, giving the big picture so that improvement possibilities can be visualized. The flow chart, I believe, will do the same for you.

There are two basic models of a woodwork plant. The first is raw material in one end and finish goods out the other. The other is a "U" shape where raw materials and finish goods go out the same end. In both cases, you want to focus your machinery in a core area to allow common dust collection, power and air runs.

When a "U" shaped plant expands, you stretch the end that the material doesn't load in and out of. The stretch on a feed-through should be on the outbound end, but could be on the inbound.

Both of the above can be made into "L" or other irregular shapes, as parts move throughout the plant on conveyors or carts.

There are a few real quality plant layout guys around. Expect to pay 4-8k with design. Part of the process is defining the manufacturing methods. In a custom business, you need the assembly, in and out feed areas to be movable for large jobs or if you want to change or edit the process.

So the first steps are
1) Manufacturing process
2) Market segments and expected growth (tells you what to leave room for now so if you buy X machine in two years, it plugs in).
3) Develop a flow-through process that accommodates your varieties.
4) Look for land and decide on building shape or decide on building shape and look for land the shape fits on.