Article:Custom Or COTS
Developers often find that there is a COTS or Off The Shelf module available which meets many of the functional requirements of the project. So then comes the question of whether to use the COTS module or continue developing very own custom module.
Some of the factors to consider:-
1. Form Factor :-- When it comes to hardware modules, form factor is very important. The module available in the market may functionally meet the requirements, but if its size and shape are not suitable then it cannot be used. Sometimes the size may be fine, but say for e.g. the data ports may be at the wrong side for your design, or may be aligned differently.
2. Operating Environment :-- The COTS module may not operate satisfactorily at the temperature required for the project. It may not be able to handle the vibrations or other stresses. EMI/EMC requirements need to be checked.
3. Security :-- Does the COTS module allow access from certain ports or methods which are not good for the project. Sealing these security leaks may be costly and sometimes not possible.
4. Cost :-- For very small numbers COTS products are the economically better choice. But if your product is being mass manufactured then developing your own module makes sense.It helps to calculate cost of manufacturing your own module and multiplying it by 1.3 to get a fair idea of actual cost.
5. Availability :-- This is the biggest issue with using a COTS product. Will the product be available in the market the next year? If so will it be available in the same form, or some newer version which is not of use? While selecting a COTS product it is important to get a commitment from the manufacturer ensuring supply for whatever duration is required by you.