Case: Circuit Board Fabricators, Inc.

Circuit Board Fabricators, Inc. $($CBF$),$ is a small manufacturer of circuit boards located in California near San Jose. Companies such as Apple Computer and Hewlett$-$Packard use the company to make boards for prototypes of new products. It is important that CBF give quick and very high$-$quality service. The engineers working on the new products are on a tight schedule and have little patience with sloppy work or missed delivery dates.

Circuit boards are a rigid flat surface where electronic components are mounted. Electronic components such as integrated circuits, resistors, capacitors, and diodes are soldered to the boards. Lines called $$traces$$ are etched on the board and electronically connect the components. Since the electronic traces cannot cross, holes through the circuit board are used to connect traces on both sides of the boards, thus allowing complex circuits to be implemented. These boards often are designed with $40$ to $50$ components that are connected through hundreds of traces on a small four$-$by$-$six$-$inch board.

CBF has developed a good business plan. It has four standard$-$size board configurations and has automated much of its process for making these standard boards. Fabricating the boards requires CBF$$s numerically controlled $($NC$)$ equipment to be programmed. This is largely an automated process that works directly from engineering drawings that are formatted using industry standard codes.

Currently, the typical order is for $60$ boards. Engineers at customer companies prepare a computer$-$aided design $($CAD$)$ drawing of the board. This CAD drawing precisely specifies each circuit trace, circuit pass$-$through holes, and component mounting points on the board. An electronic version of the drawing is used by a CBF process engineer to program the NC machines used to fabricate the boards.

Due to losses in the system, CBF has a policy of increasing the size of an order by $25$ percent. For example, for a typical order consisting of $60$ boards, $75$ boards would be started through the process. Fifteen percent of the boards are typically rejected during an inspection that occurs early in the manufacturing process and another $5$ percent of the remaining boards are rejected in the final test.

Board Fabrication Process

CBF purchases circuit board blanks from a vendor. These boards are made from woven fiberglass cloth that is impregnated with epoxy. A layer of copper is laminated onto each side to form a blank board. The blank board comes from the vendor trimmed to the standard sizes that CBF$$s numerically controlled equipment can handle.

The following is a description of the steps involved in processing an order at CBF:

Order acceptance. Check to verify that the order fits within the specification of boards that can be produced with CBF equipment. The process engineer at CBF works with the customer engineer to resolve any problems with the order.

NC machine programming. CAD information is used to program the machines to produce the order.

Board fabrication.

Clean. Each board is manually loaded into this machine by an operator. The machine then cleans the boards with a special chemical. Each board is then automatically transferred to the coating machine.

Coat. A liquid plastic coating is deposited on both sides of the board. Following this process, an operator places the boards on a cart. Each cart, with a complete order of boards, is then moved immediately to the $$clean room.$$

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Expose. This photographic process makes the exposed plastic coating resistant to dissolving in the areas where the copper traces are needed. An operator must attend to this machine $100$ percent of the time, and load and unload each individual board.

Develop. Each board is manually loaded onto this machine. The boards are dipped by the machine, one$-$at$-$a$-$time, in a chemical bath that dissolves the plastic and the underlying copper in the proper areas. After dipping, the machine places each board on a conveyor.

Inspect. Each board is picked from the conveyor as it comes from th

What type of process flow structure is CBF using? What other types of process flow structures could have been used? Compare and contrast these structures and explain which method$($s$)$ would be feasible for use at CBF and which one would be best for CBF$,$ if different from the structure CBF is currently using.

Analyze the capacity of the process. Are the capacities of all the processes$/$machines balanced? If some are not, which processes$/$machines are they and can you determine a cause for the imbalance?

What is the impact of the losses in the process in the inspection and final test?

List and fully explain the recommendations would you make for a short$-$term solution to CBF$$s problems? How would you define $$short$-$term solution$$ to CBF in terms of days or months?

What long$-$term recommendations would you make? Describe why these recommendations are different from your short$-$term solutions.