What is VSM / Value Flow Chart and what is it for?

Material and Information Flow Diagrams were originally developed by Taiichi Ohno and Toyota's Operations Management Consulting Division to help suppliers learn the Toyota Production System.

Later, in 1999, Mike Rother and John Shook adapted the Toyota techniques and turned them into what we know as "Value Stream Mapping". Value Stream Map is a visual representation of the process flow and information.

VSM is used to locate where improvement is needed in a stream. Whether it is for bottlenecks, large stocks or delivery time, VSM is the "compass" then the problem is addressed through an improvement project.

Unlike other mapping tools, VSM shows the link between information flow and material flow. The information in the process can be: time cycle, raw material stock, equipment capacity, stock of semi-finished products between processes, number of operators, stock of finished products.

Terms often used in VSM are:

• Bottleneck = any resource whose capacity is less than the command received
• Constraint = anything that limits a system in achieving the highest performance or productivity;

One of the key information we need to find and identify in VSM is whether we have a longer cycle time in the manufacturing flow than the tact time given by the customer and to identify measures to reduce them.

As the application structure of a VSM there are two levels: the initial state and the future state. In order to perform a VSM we must follow the steps below:

• Identifying the product family and the process
• Collection of relevant data
• Current State Map
• Identification of process losses
• Identification of process bottlenecks
• Analysis of data from the current stage of VSM
• Future State Map
• Implementation and optimization plan

The VSM is performed by a multidisciplinary team that includes a moderator, with expertise in VSM technique.

So why should we use VSM? To identify where to intervene to become more competitive.