“What is a storefront and how can it help my lean manufacturing system be more flexible?”
I haven’t found a reference to a “storefront” as such in any lean sources. Storefronts are the interface between the customer and the producer. That fact makes this a key concept in the customer-focused lean culture. There are at least three ways that storefronts can enhance lean manufacturing systems.
The first thing we think of when we hear storefront may be the supermarket system. Supermarkets are well-ordered stock keeping locations within a value stream that are designed to enable pull systems between upstream and downstream processes. The removal of the work in process or finished goods inventories within a supermarket gives the signal for replenishment to the upstream process. The supermarket by itself does not help a lean manufacturing systems be more flexible. Synchronization of the processes within the value stream based on a single downstream scheduling point (i.e. pacemaker) using logically defined buffers (supermarket) can make lean systems responsive to changes in demand.
The second example of a storefront concept applied to make lean manufacturing systems more flexible is the yatai system. The yatai is the Japanese word street vendor cart seen across Asia, not unlike the New York City street corner hot dog stands. It is a small, simple, mobile, temporary storefront that allows a chef-proprietor to serve 1-4 customers fresh food on demand.
Many Japanese companies adopting lean manufacturing methods use the analogy of the yatai to help people understand and accept the logic of a small, flexible production cell. The yatai system is what we would recognize as a flexible manufacturing workstation that contains the parts, tools and jigs necessary to complete the entire process, such as assembly, inspection and packaging.
These yatai are so popular that you can buy one on the internet and start your own lean eatery. Food service license not included.
The third example of a storefront within a lean manufacturing system is what I recently heard called a fish market. Many of us know this by another name such as the defect display, sample board or scrap table. The fish market is a small table at or near the production area, typically by the team communication board. It is used to display the latest defects during the team leader meetings. It is used both to raise awareness among team members about the defects that were produced on the last shift, as well as to call engineers, managers and support staff to action on taking root cause countermeasures. Like fish, the defects should be “sold” or taken care of that day, because old fish begin to smell bad. Size the fish market appropriately small to force rapid response.
There is nothing like showing the actual defects in the actual workplace, rather than as data on a computer screen or on a table in a conference room. The genchi genbutsu principle requires leaders to go see on a routine basis. The supermarket, the yatai and the fish market all create simple, visual standards that make it easier for leaders to see and respond to problems quickly.