Introduction to Engineering product development

Engineering product development is essential for the comfort of man and development of nations. All the major economies of the world, like US, Germany, Japan, Korea, China have companies that make engineering products that are sold across the world. New products, efficient process are the key wealth of the nations.

New product development is not just about things that appear in news like cars or computers, they make news because they are sold directly to consumers. Better products and process are introduced in industries and lead to huge gains for the society.

I will try the explain the process of Engineering product development using an example of a electric wheel chair. Lets say a group of engineers want to develop a electric wheel chair. Its not a rocket science or a cutting edge R&D, its a product that requires engineering.

User Requirement: At each stage it is extremely important to understand the users requirement and review it repeatedly. It is usually seen that there is a big gap between engineers and their end users. This affects the product development negatively. This is an iterative process.

Multidisciplinary: This product (and many others) is a combination of, mechanical, electrical, electronics/controls and computer science engineering. It is always good to have friends from other branches of engineering. One should be capable of appreciating and understanding the subjects from other branches also. Never have this attitude, “I am a xyz Engg, so I have no idea of other engg.”

Gross BoM: Then make a gross Bill of Materials or list of important parts. The wheels, the structure of the chair, the bearings, motors, battery, control stick, PCB, display or indicators. Once you have the gross BoM, find out which parts can be made lighter, cheaper, or more efficient. Here are a few examples, the battery can be same as a car or 40 mobile batterys in series. Can the PCB be same as used in toy cars? Can the bearing be same as used in cycle, scooter, motorbike? What are the advantages/disadvantages of each options. Example, if you use mobile battery, they can be replaces one by one, while a car battery change will cost more? Or the charging time of each?

Gross calculations: Make a gross calculation of the major components. The wheel chair is for patients till 50kg or till 80 Kg. Then calculate the required torque for plain surface, or for inclined surface of 15deg. On the basis of torque required, you will calculate the power of the motor required, then the battery required to run the motor for a few hours. All this, will give you an idea of the control system required to maneuver the wheel chair. Make control algorithm, and a drawing showing what the product may look like.

References: Why not Google it, ya sure!!. Find out what others have done, mistakes they made and learn from them.

Detail Calculations: After a few iterations of gross BoM and gross calculations, you have to do the detailed calculations and show it on paper that the wheel chair with the selected components, like chair, wheels, bearing, motors, battery will work under the given environmental conditions. At this stage you will also finalize, where each of this components is kept, and the control algorithms.

Detail Drawings: Now is the stage of detail drawing, preparing final Bill of Material and making assembly drawing, work instructions and sourcing the components.

Design Standards: Most of the engineering products, from a door knob to aeroplane, have to adhere to certain design standard,. There are Indian standards (ISI) , German standards (DIN), international standards (ISO). There are standards for the components, drawings symbols and every smallest of the details, even the nut bolts that you use. If you want to make a product that is of high quality and is acceptable world wide, then you choose the appropriate standard and make sure your calculations and drawings fulfill those standards. For example, bolts and nuts are as per ISO 4016 or 4018 depending on application and there are separate standards for washers.

Documentation: At each stage, it is extremely important to have a good documentation. Make tables, charts, of the requirements, calculations etc. This is extremely important when making decisions or reviewing decisions.

Further development: Always document further advancement that are possible in this product. For example, the wheel chair can be made using a direct drive motor or can have a regenerative braking, i.e. Which generates electricity on braking.

The future needs of humanity asks for more efficient products that have longer life spans, are more reliable, have less impact on environment in their production or operation. Great companies have begun with small products and new ones continue to be build on strong engineering foundations. A example is DEHN, a German company dedicated to lightning protection only or SVENDBORG that makes brakes only.. They make high quality engineering products and test these products to high standards. Good engineering teams are an asset to the nation.

Abhinav Bhatnagar

2000 Electrical

Mar 2011 for SRIJAN , MNNIT College Magazine