How to determine hardware requirements
Your hardware requirements are typically generated from three sources; the product requirements, risk management and design-specific standard’s requirements.
Hardware requirements derived from product requirements are predominantly functional. To define the requirement, we have to ask ourselves: “what does the hardware sub-system need to do, or contribute, in order to fulfil each product requirement?”
In some cases, a hardware requirement will fully cover a product requirement, but in other cases it may only be one of several elements needed. For example, a requirement to control temperature may involve the need for software, system and mechanical requirements, as well as hardware.
The risk management process, typically a design Failure Mode and Effects Analysis (FMEA), may identify additional hardware requirements as risk reduction measures. For example, an independent overtemperature cut-out may be required as a risk mitigation for a temperature controller failure.
International standards such as IEC 61010-1 and IEC 61010-2-101 are written by industry experts and, whilst they may seem like just a necessary hurdle to marketing a product, they usually contribute to a more robust and safer design output. To minimise the risk of non-compliance when the final design is tested to these standards, it’s prudent to thoroughly review the standards in relation to the specific design and produce design-specific standards requirements.
The hardware requirements should, as far as possible, be design independent, focusing on what’s required rather than how to implement it. They should be succinct, necessary, unambiguous, singular and verifiable.