Lean Tool of the Month-Value Stream Mapping

Value Stream Mapping is an exercise to identify the value added steps of a process and more importantly, the non-value added steps and delays in a process. The reason to do this is to identify where waste and rework and bureacracy occurs in a process and seek ways to streamline by removing unnecessary steps, loops and approvals from the process so that only the value is left in the process. By the way, a word on value. Value is defined by the customer. The customer is not always the paying customer at the end of a process waiting for their product or service that they ordered, but can be the next process owner down the line towards fulfulling the paying customers' needs. Value, generally speaking, is steps that move the product or service towards the customer. Any thing that does not contribute to that value chain is waste. Some might say that product inspection is valuable because it ensures that the customer gets what they want. While it is true from one perspective, from the value-chain perspective, inspection is not something that moves the product towards the customer. In an ideal world, where high quality is present, inspection is not necessary. Inspection is therefore, a non-value added activity. Since we don't live in an ideal world, some non-value added activities are required. View them as necessary evils and seek to reduce them whenever possible.

The first premise of value stream mapping is that it starts with the customer. Since mapping in reverse is a metally tough exercise, we typically will map starting with the supplier, through all of the work process steps and data exchanges to the customer. Once the map is built however, we must look critically at the steps of the process through the eyes of the customer and determine what is valued and what is not. During the mapping exercise capture any wait times or delays or rework loops or approvals that occur along the way. Capture data exchanges, manual or electronic forms that get filled out all the way back to the start of the process, including the supplier. As you complete this exercise, the NVA will jump off the page and where the improvement opportunities lie will be obvious.

Value stream mapping is an effective tool. I have used it to remove significant chunks of time from processes that I was improving, and so can you.

Below is an example of a value stream map of the "As Found" process

and here is the improved process

This improvement saved 26 days of cycle time.