“Portable.” “Affordable.” “Accurate.” “Long battery life.” These words sound like product requirements, but they are too vague to guide an engineering decision or a test.
Before choosing components or drawing a schematic, a development team needs to turn the original idea into a clear problem, a focused project objective and measurable requirements.
Write the problem without locking in the solution
A useful problem statement explains who experiences what problem, in what context and why it matters. It should describe the need before committing to a particular board, sensor or software platform.
Weak: “We want to build an Arduino automatic irrigation system.”
Stronger: “Small-scale growers often rely on visual judgement to decide when to irrigate. This can cause inconsistent watering and unnecessary water use. A low-cost method of monitoring soil conditions and controlling irrigation could reduce manual effort and improve consistency.”
The stronger version gives the team room to compare technical approaches. It also creates a basis for user research and testing.
Define a realistic project objective
The objective describes the engineering endpoint you intend to reach. It should connect the deliverable to the problem and make the level of completion clear.
For example: “To design and bench-test a low-cost electronic irrigation controller that measures soil moisture and activates a pump when moisture falls below a defined threshold.”
This objective does not promise to automate an entire farm. It identifies one core function and one realistic test environment.
Build a complete project statement
A strong early project description should capture:
- the observed need or problem;
- the target users and other stakeholders;
- evidence that the problem is significant;
- how the problem is handled today;
- the limitations of current solutions;
- major technical or contextual barriers;
- the expected measurable improvement; and
- the project objective and planned deliverable.
Know the difference between a requirement and a specification
A requirement is something the product must satisfy. A specification expresses that requirement in a precise, testable form, usually with a metric and target.
Good requirements are complete, measurable, feasible, unambiguous, non-conflicting and traceable to a real need or constraint.
Turn soft expectations into measurable targets
- “Must be portable” becomes “The assembled device shall have a total mass of 500 g or less.” Test it with a scale.
- “Battery should last long” becomes “The device shall operate for at least eight hours under the defined normal duty cycle.” Test it with a runtime trial.
- “Should detect high water” becomes “The alert shall trigger within ±2 cm of the defined level threshold.” Test it in a controlled tank setup.
- “Should be affordable” becomes “The prototype bill of materials shall not exceed GHS 400.” Verify it with a BOM cost review.
- “Should be easy to use” becomes “A first-time user shall complete the primary task in no more than three actions.” Evaluate it with a usability trial.
The exact targets will differ from project to project. What matters is that the team can inspect, calculate or test them objectively.
Include the constraints that shape electronics
Requirements should cover more than the headline function. Consider:
- supply voltage, battery type and power consumption;
- temperature, humidity, dust and noise conditions;
- size, mounting, enclosure and connector access;
- component availability, substitutes and lead time;
- prototype budget and future unit cost;
- signal accuracy, response time and sampling rate;
- communication range and connectivity;
- safety, isolation and protection; and
- ease of manufacture, assembly, repair and firmware updates.
Requirements make later decisions easier
Once requirements are written, component selection becomes a comparison against evidence instead of personal preference. Schematic reviews have a purpose. PCB constraints have a reason. Most importantly, the team knows what to test.
If you are developing an electronic product and need help defining requirements or translating them into a robust design, explore our engineering services or contact CircuitWise Consults.