How well a product performs in the marketplace is almost entirely determined by the product’s conceptual design (see). However, most of the product development cost is in the detail design phase. It follows that if the conceptual design is not optimized, you may spend a lot of money and get very little from your product development investment.
How do you know if the conceptual design is optimized? Well, first, make sure you follow a proven process and conduct a good requirements analysis.
A Requirements Analysis (RA) is a method of determining if the conceptual design will meet the product requirements. This analysis is the final vetting before big money is spent, so it is wise to complete this phase of product development with some TLC.
The best RA processes use an independent team to do the RA, and they use different types of analysis for each category of requirement.
Although every product is different, and therefore every product requirements are different, most have the following types/categories of requirements:
- Cost and Schedule
Each category has its own set of RA methodology.
Functional: It is easy to gloss over the functional requirements. However, this is exactly the reason you should not skip over Functional RA — everyone is assuming they got the basics correct.
For each functional requirement, write a description of how the system, and its elements, accomplish this function. You may be surprised how often a key part is left out of the Conceptual Design (CD).
Performance: How do we know that the system components will meet the performance requirements? A good rule is that if you can not point to those components in a released product performing to the requirement performance level, then a Proof of Concept (PoC) test must be performed.
Compliance: The best practice for RA of compliance requirements is to meet with third-party testing/certification companies and review the CD with them. Although they will never tell you it will pass, they will get you 90% of the way there as they are the experts on the standard.
Cost and Schedule: Cost breaks down into two parts — unit cost, or COGS, and development cost.
Doing RA on is simple enough — develop a spreadsheet with the BOM and labor cost. Don’t forget to review this spreadsheet with your vendors. They are the experts on manufacturing cost.
For development cost, create a drawing tree of the product based on the CD and get each engineer responsible for estimating the labor, testing and material cost for developing each assembly. Add management and overhead, and you will have a good estimate of the investment needed for the detailed design phase.
The same drawing tree method can be used to determine the schedule.
Note: many engineers will balk at estimating man hours — especially if they have never done it before, as they will almost certainly be wrong. However, point out that they can not get better at estimating cost unless they practice. This is also why it is really important to review these projections after the detailed design phase so the team can improve.