Once the non-value added, unnecessary steps have been eliminated, we can look for flow of the remaining steps. In this step, we seek to eliminate wait times and the compartmentalisation of the workflow.
The attempts to improve the departmental efficiency can create waste in the product value stream if the departmental efficiency produces outcomes that do not serve the customer needs, or requires inputs that increase costs for suppliers without adding value. While standardisation of product components make the individual processes more efficient, this efficiency can come at the cost of customer value. Think about the usual new car purchase experience. You buy “the package” which includes things you are paying for but do not need, because it is more efficient for the production and delivery processes.
This batch-imposed waste is compounded if changes occur in design or customer needs, as the WIP or final good inventories require rework or become scrap. Note that these concepts are not limited to manufacturing; businesses in the service sector can also generate waste. Think of the hamburgers cooked in advance, waiting for an order, or checking account statements that come at the end of the month, long after you could possibly prevent an overdraw. Transparency helps to increase the awareness of these types of waste.