CAD Is Not Engineering: Why the Best Engineers Start With Requirements
One of the most common mistakes I see engineers make is opening CAD before they understand the problem. That might sound strange coming from a mechanical engineer who has spent decades designing products. CAD is an essential tool. Modern engineering would be nearly impossible without it.
But CAD is not engineering.
Engineering is the process of making decisions to solve a problem within a set of constraints. CAD is simply one tool used to document those decisions.
Why Engineers Jump Into CAD Too Early
Most engineers are taught technical tools before they are taught systems thinking. As a result, many projects begin with sketching concepts, building CAD models, creating assemblies, and debating design details.
Before anyone has clearly defined the customer need, the requirements, the performance targets, the cost objectives, and the manufacturing constraints.When this happens, teams often spend weeks optimizing the wrong solution. The cost of skipping requirements is a lot. I’ve seen projects fail because teams designed elegant parts that solved the wrong problem. The CAD looked great. The drawings were complete. The prototypes worked. But the product missed cost targets, couldn’t be manufactured efficiently, or failed to address the customer’s actual needs.
Every one of those failures started long before the CAD model was created. They started with unclear requirements.
The HatchOne Product Development Process
At HatchOne, we teach product development as a sequence of decisions:
Define (WHY)
Understand the customer, market, and problem.
Questions to answer:
What problem are we solving?
Who has the problem?
Why does it matter?
What does success look like?
This is where the Market Requirements Document (MRD) lives.
Design (WHAT)
Define what the product must do.
Questions to answer:
What functions are required?
What performance targets must be met?
What constraints exist?
This is where the Product Requirements Document (PRD) lives.
Engineer (HOW)
Only now should detailed design begin.
Questions to answer:
What materials should be used?
What manufacturing processes are appropriate?
How will the product be assembled?
What tradeoffs are necessary?
This is where CAD becomes valuable.
Prototype
Build, test, learn, and iterate.
Produce
Launch a product that can be manufactured consistently, economically, and reliably.
What Great Engineers Do Differently
The best engineers I’ve worked with share a common habit. They spend more time asking questions than drawing parts. They seek context. They challenge assumptions. They understand the tradeoffs before they begin designing solutions.
Most importantly, they recognize that every line in a CAD model represents a decision that should already have a reason behind it.
The Career Lesson
Learning CAD can help you become a designer. Learning requirements, systems thinking, and decision-making can help you become an engineer. As AI and automation continue to accelerate technical tasks, the ability to understand problems, evaluate tradeoffs, and make sound decisions will become even more valuable.
The future belongs to engineers who understand not only how to design parts, but why those parts need to exist in the first place.
Start with the problem. The CAD can wait.