Determining the Design Goal

The overall goal for any embedded designer can be summed up quite easily:

Better, faster, cheaper.

• Better in the sense that you choose a high-quality hardware solution that perfectly matches the system requirements with the minimal number of components and with excess horsepower for the inevitable feature-creep that any product faces during development. The ideal choice would include all necessary memory and peripheral functions onboard, occupy minimal space, and consume almost no power.

• Faster by bringing the product to market in the least amount of time possible, preferably before your competition even knows the work has begun.

• Cheaper for the obvious reasons—the lower the cost to the customer, the higher the volume. The higher the volume, the more profit per engineering dollar spent.

Of course, reality dictates that not all of these goals can be achieved simultaneously, as the experienced designer knows. In fact, satisfying any two of these goals represents a remarkable accomplishment and is the practical upper limit. Therefore, your first and most essential task is to select the one main objective that is the ultimate aim of your project: better? faster? or cheaper? This information helps drive all subsequent processes because it forces you to focus on what’s important. If you’re trying to beat the competition to market, you need to work fast; you can give up some cost advantages by using off-the-shelf parts instead of engineering and building your own. However, if you’re designing a system that will control equipment that can endanger human life, your overriding concern is quality; you’ll take the time necessary to ensure quality, and spend the money on higher-quality parts. If you need to build the least expensive box possible because your quantities are immense, you’ll spend the time engineering the box and live with tradeoffs on quality.