What’s an Engineering Requirements Document and Why Should I care?

A Requirements Document (RD) is a controlled document that specifies the “what” of a product but not the “how,” that has yet to be designed.

We are going on this product development journey, and the RD tells us where we are going to — the destination. We don’t know how we will get there yet — plane, boat, train, car — or the exact route, but with a RD, we do know the destination. At the end of the project, we will use the RD to define a Design Verification Test (DVT). If the product we designed meets the requirements, as shown by the DVT, then we know we have arrived at the correct destination — which also defines “done” for the product development project.

So, why is an RD so important? Well, if you do not know the destination, then any direction will do (said the Cheshire Cat to Alice). If we have not defined the Requirements, then any design will do. We can use any concept we feel like. This material will be just as valid as that material. Etc., etc….

This failure to define the goal is one reason product-development teams struggle to make decisions. The lack of clarity causes teams to have endless conflict about this idea vs. that idea. Decisions are delayed, consensus making impossible, and trust erodes as each defines their own reasons for the promotion of their pet idea.

Meanwhile, there sits the customer — the one whom we all agree we are designing the product for. Without a RD, he has no voice in this conversation — no wonder the lack of a good RD makes it 300% more likely the product will not have product market fit.

With a RD, all ideas can be judged on how well they meet the requirements. Decisions become easier, clarity of purpose is solidified, trust increases as it is clear everyone is working towards a common goal.

If we commit to making a RD, the product will be much more likely to have a product-market fit, significantly increasing the likelihood of a positive ROI. You see, the process of creating a RD, along with the accompanying Market Validation experiments, forces you to view the product through the customer’s lens. Quantifying the requirements creates clarity, and the accompanying enumerations strip away complexity.

Hopefully, I have fulfilled my requirement for writing this blog — convincing you to write requirements before getting too far down the product development path. If I have, see our Requirements Document Template here.