On the basis of the nature of design problem, design may be classified as

•  Selection design
• Configuration design 
• Parametric design
• Original design
• Re-design

Selection Design

It involves choosing one or more items from a list of similar items. We do this by using catalogues. Eg. -Selection of a bearing from a bearing catalogue-Selection of a fan for cooling equipment-Selecting a shaft.

 • Configuration / Layout / Packaging Design 

In this type of problem, all the components have been designed and the problem is how to assemble them into the completed product. This type of design is similar to arranging furniture in a living room. Consider the packing of electronic components in a laptop computer. A laptop computer has a keyboard, power supply, a main circuit board, a hard disk drive, a floppy disk drive and room for two extension boards. Each component is of known design and has certain constraints on its position. For example, three xtension slots must be adjacent to the main circuit board and the keyboard must be in front of themachine.KeyboardMain Circuit board Extension slots Floppy drive Power supply The different components are shown above. The designer's aim is to find, how to fit all the components ina case? Where do we put what? One method for solving such problems is to – select a componentrandomly from the list and position it in the case so that all the constraints on that component are met

 

 Let's take keyboard first. It is placed in the front. Then we select and place a second component. Thisprocedure is continued until we reach a conflict, or all the components are in the case. If a conflict arises,we back up and try again. Two potential configurations are shown above.

 • Parametric Design

Parametric design involves finding values for the features that characterize the object being studied

gives a possible solution for the design problem.

• Original Design

As described in an earlier section, an original design in the development of an assembly or componentthat did not exist before.

• Redesign

The redesign is a modification of an existing product to meet new requirements. It is same as adaptivedesign. Most design problems solved in industry are for the redesign of an existing product. Suppose amanufacturer of hydraulic cylinders makes a product that is 0.25m long. If the customer needs a cylinder 0.3m long, the manufacturer might lengthen the outer cylinder and the piston rod to meet this specialneed.

 

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