When I was doing some surveys of subcontractors, I joined one of our supplier quality people to survey an Uninterruptible Power Supply vendor. What we found was the leanest operation I have ever seen. Coming from a contract based Project Engineering environment, the planning methods were a real eye opener to me.
At this company, there were only 6 people plus the President who did not actually build or rework units. The manufacturing pool was easily 30 or 40 people, and swelled to much larger at rush times. No line managers. How did this work?
The people who were not assemblers:
The President
A Salesman
An Engineer
A Purchasing Agent
A Line technician that verified the Quality of the units
A Material person who did Kitting
A person who handled Shipping/Receiving/Fulfillment
The sales engineer would analyze the market, which was mostly handled by distributors who worked on commission. Based on their expected needs, and number of units remaining in stock, he would enter the number and types of units to build on speculation into the Enterprise Resource Planning (ERP) system.
This was then approved or modified by the President, who also did the books for the company.
Upon approval, the ERP system would then explode the Bills of Materials and combine like items for the units, and push the Purchasing person detailed lists of material to procure. The ERP system also took into account existing stock.
When the material came in, it was logged as received by Shipping/Receiving.
The kitting person would receive notification from the ERP system of which kits were could be completed, based on received material. She would then kit up units based on the material available, and place them on shelves for the assemblers. No one told her how many or which ones to do. She put together the ones she could.
The assemblers would arrive at the plant, go to the shelves that held the kits. They would select one that they were familiar with, and build it, and put it on the completed shelf. They would do this as long as there were units to build, and go home when there weren't any more. If there were a lot of kits, they would tell their friends, and they would come in to add more units.
The Quality person would take units off the completed shelf, check units over, test them, and take passed units to shipping and set them there.
Out units would go, to inventory or to a customer.
The engineer designed the products, trained the operators, and debugged any returns. There was a shelf for repairs/failed units he would check regularly.
Personnel Management was subcontracted to an agency that handled all that stuff.
The thing that is totally missing from this model is any sort of time based planning. That's right, they didn't track what would be completed when. They didn't have manufacturing planners deciding to do six Model 206s today, and five more tomorrow. Everybody worked on what was in front of them, based on what was complete and ready to do. The day to day operation, basically, just happened. The ones they had, they could sell. The ones they didn't have, they couldn't.
The system was front loaded by the number of units entered into it, and whatever units could be built spilled out the back on a schedule that was not controlled in any way. Occasionally, the President said he gave specific direction for procurement or assembly. But he said he rarely did this, and concentrated on selling the units they produced.
A completely events driven company.
If you combine this with the Serial Method of design, you have a corporate culture completely without traditional time and task based management. There are no schedules, per se, but only states that the design or manufacturing of any product is in. The whole layer of mid-management is just not there.
Since my background is in schedule compression, this was pretty foreign to me. They really didn't know how many of what type of units would be produced next month. It depended on lots of factors they didn't monitor or control. As long as the cash flow was ok, there were no issues with letting people pick what they did next. Holdups were handled on a exception basis.
In the end, it is all about cash flow. If you can accomplish that without planning, why bother?