When starting an innovative project, it is common to ask a partner for “a prototype” or “a POC” without being sure which one is needed. The terms are often used loosely, yet they correspond to different deliverables, answering different questions, with different costs and timelines. Asking for the right one avoids paying for more than you need, or receiving less than you expected.
Feasibility study: is it possible, and how?
A feasibility study is primarily analytical. It clarifies the need, reviews possible technical approaches, identifies risks and constraints, and estimates costs and timelines. Its deliverable is typically a report with a recommendation and a proposed roadmap. It is the right choice when the need is still taking shape, when several technologies are possible, or when you must justify an investment before committing to it.
Proof of concept: does the critical part work?
A proof of concept (POC) tests one specific, uncertain point, often the riskiest one. Can this model detect the defect with sufficient accuracy? Can this sensor work in these conditions? Can this radio link cover the site? It is deliberately narrow and quick, built with whatever tools allow the fastest answer. Its deliverable is evidence: test results against criteria agreed in advance. A POC does not show that the full system will work, only that a key obstacle can be overcome.
Prototype: does the whole system work in practice?
A prototype brings the elements together into a functional system representative of the final solution, which can be tested by users in real conditions. It validates integration, usability and overall performance, and it reveals the practical issues that isolated tests miss. It costs more than a POC, and it is still not a product: industrialisation will require further work on robustness, security, manufacturing and support.
How to choose
Choose according to your main uncertainty. If you are unsure what to build, start with a feasibility study. If you know what to build but doubt that a critical element will work, commission a POC. If the key risks are resolved and you need to validate the complete solution with users, build a prototype. Many projects go through all three, each one reducing risk before the next, larger commitment.
Whatever the deliverable, agree in advance on the question it must answer and the criteria for success. That is what makes the result useful for your next decision.