During the industrial revolution, technology became more complex.  The complexity forced forced employees of companies to specialize in different areas of the product design process.  No longer could one person be responsible for the design, manufacture and sales of a product.  The era of the craftsmen gave way to the era of the specialist.  Large companies begon to organize their into departments with different responsibilities.  Some examples of departments and responsibilities are shown below.

1. Marketing – Tries to understand the future needs of the customer.
2. Research – Develops the technology to meet the needs identified by Marketing.
3. Design -Uses the technology developed by Research to design products to mee the needs of the customer.
4. Manufacturing – Devlops the methods to manufacture the products designed by the desing department.
5. Sales – Develop plans and executes the plans to sell the products to the customer.

The design process was then organized into a linear system as shown in Figure 1.

Figure 1. The “over-the-wall” design process.

Each deparment worked on a product until they had completed their tasks and then they handed off the project to the next department.  Not only was this serial process very slow but it also caused many problems when the communication between departments broke down.  The breakdown of communications led to projects being thrown back over the walls that divided the departments for rework.  This reverse flow of projects is shown in Figure 2.

Figure 2. The “over-the-wall” design process with reverse flow.

Some typical reasons for reverse flow are listed below:

1. Marketing specifies a need that research can not develop a technology to meet.
2. Research develops a technology that is too expensive or not robust enough to use in a product.
3. Design creates a design that in very difficullt and expensive to manufacture.
4. After many changes to meet the demands of each department manufacturing produces a product that does not solve the customer’s problem or is to expensive.

The concurrent engineerinng design process was developed to adress these problems.  Click here to learn about concurrent engineering.