Product Design includes Schematic and Firmware Design. The Mechanical Engineering that goes into making the enclosure and internal construction is also important. The Electromechanical design which is made of electrical circuit, pcb, panel-parts and cable management is sometimes so involved that it is developed with the help of vendors or suppliers.

Product design engineering also needs to take care of the costing and related issues. The costing includes the one time investment on design and tools, even custom Mold-Die, Jigs-Fixtures etc. The engineering costs are amortized over the quantity produced, in a product type life-cycle.

Manufacturing small quantities is expensive, large quantities depends on marketing and customer base. Hence custom product manufacturing is a specialized technology all-together, this needs to be modular, programmable and configurable.

• Just like in ICs, product design is of three types commercial, industrial and military or medical.
• Quality: cost effective design, quality components, quality workmanship with good testing can result in a quality product. The packaging and production engineering too is important.
• Whatever be the specs, design or simulation nothing like a prototype being tested by the customer in his environment. So do not go into volume production till such a test is done.
• Design as per inventory : when you design a new product, we can design it with new types of parts, but it is also important to use parts that are standard to the company’s inventory, Also you need to use up the parts which have been accumulated due to a discontinued product line or a failed idea. This way the design becomes more frugal and efficient. It also saves the company to build a new part type stock.
• A Temperature Controller was fixed in a PCB manufacturer’s Works, The readings was fluctuating and soon stopped working properly, the service engineer went and found that there was a strong smell of ammonia around the unit. When opened the tracks were eaten away by rapid corrosion and some of the component leads had disappeared. So another controller was made with extra coats of lacquer-varnish all over and RTV compound in many places. That solved the problem. For large numbers vacuum impregnate modules in epoxy resin.
• Reworks or fixes will add rapidly to the BOM bill of Materials Cost. Then cost of servicing. So customers are of five types home-user, industrial, hazardous, military and medical. So Components are to be selected and product engineered and costed accordingly in that order.
• If a product gives three years life with minimum service support it can save itself from building a bad reputation. six years will establish the brand on a long term basis, twelve years of product life you will have the user of the product selling for you. if you want to improve sales by giving a new model every three years, you will need a lot of innovation on the product and you need to buy back the old ones for a big discount, you can bear some cost for brand loyalty and hence build a reputation for more sales in the future. This implies proper and sensible investments in product design and development, engineering, reliability, standards and quality will help a company survive long term.
• Theory and simulation can give you only part of the picture, you have to breadboard to test properly.
• In schematic indicate pin numbers of every IC or map the correct part if manual place and route is used.
• Keep functional blocks of circuits as modules or separate areas in a big PCB, this helps in testing and troubleshooting.
• When you design an equipment keep the controls minimum, too many options and too many knobs and dials are not good ergonomics . For your equipment to be user friendly use simple navigation and not menus nested 6 deep.
• Power circuits, digital circuits and analog circuits should have separate supplies and ground when possible.