In every manufacturing process, our aim is to add value to a product that the customer will pay for. While adding value to our products, there are tasks that must be done to complete the work but don’t directly add value; set-ups and inspection, to name a few. Then there are the other activities that occur during production that are waste.
How do we begin to “See” the waste in our production systems? Before beginning on our Lean journey, as long are people look busy and the machines are always running, then we thought things were good. Once we begin to investigate the value added steps and cycle times in our process, through a Value Stream Map, and compare this with the overall lead time it takes to get a part all the way through to completion, we realise that there is a BIG difference. And this big difference in times is where we can begin to focus on and discover the waste that’s hidden.
In traditional manufacturing, the waste isn’t always obvious. It’s like the bubbling stream on the left; looks lovely – it’s full of inventory. Some parts will wander to the left, others will get stuck. The problems are hidden. Lots of inventory often means lots of double handling, as we have to shuffle it around. Quality problems are hidden and rework levels are high. Over processing or over producing parts is simple part of the way we work. And trying to find anything?!? Well, good luck!
As we progress towards the channel of production and inventory levels are reduced and lead times become stable, the waste will begin to appear. Large batches need to be reviewed; reducing set-up times will allow for smaller batches. Quality issues are easier to identify. Improved housekeeping makes it easier to find things.
This is where all of the Lean tools begin to fall into place. Understanding your value stream and tacking the current wastes head on, will lead you to a continuously improving company.