What is Extended Value Stream Mapping? An extended value stream is simply all of the actions — both value-creating and wasteful — required to bring a product from raw materials into the arms of the customer. The relevant actions to be mapped consist of two flows: (a) orders traveling upstream from the customer (or from the sales department when forecasts substitute for confirmed orders) and (b) products coming down the value stream from raw materials to customer. Together these constitute a closed circuit of demand and response.
Value stream mapping is the simple process of directly observing the flows of information and materials as they now occu , summarizing them visually, and then envisioning a future state with much better performance.
Maps of the extended value stream can be drawn for products currently in production or for future products being planned. The only difference is that the “current state” map for a product in production shows conditions as they exist today while the “current state” map for a new product shows the “business as usual” approach to making the product compared with alternative “future states” and “ideal states” with less waste and greater responsiveness.
Selecting a Product Family The whole point of value stream mapping is to disaggregate operational issues to the level of specific products, where they can be more easily acted on by managers. To do this you need to start at the furthest point downstream (toward the customer) to be mapped and to define product families at that point. Typically a product family will include a group of product variants passing through similar processing steps and using common equipment just prior to shipment to the customer. For example:
In a power tools business, a product family might be medium-sized electric drills utilizing a common chassis and passing through a common assembly cell as the last manufacturing step, even though the finished product has many different features and customer labels. Alternatively the mapping team might define the product family as the motor going into the medium drills and map back upstream from that point.
In the auto industry, a product family might be a car platform (e.g., Ford Explorer and Mercury Mountaineer) produced in an assembly plant. Alternatively it might be a major component supplied to auto assemblers — let’s say an alternator — using a common design architecture and assembled in a cell, but with varying power outputs and with different attachment points for different vehicles.
PART I: GETTING STARTED