Automation in Mechanical Engineering: Meaning, Uses, Skills

Automation in mechanical engineering means using software and programmable systems to do repetitive engineering work — generating CAD models and drawings, controlling machines, running production lines — with less manual effort and fewer errors. It spans three areas that are often mixed up: CAD automation, PLC and machine automation, and industrial automation systems. This article explains each, where it is used, and which skills a mechanical engineer should learn first.

What automation means for a mechanical engineer

A mechanical engineer's week is full of work that follows rules: the same bracket in twenty sizes, a drawing sheet for every variant, a BOM exported after every change, a machine cycle that must run the same way every shift. Automation is writing those rules down once — as a program, a macro, a PLC routine or a configured system — so the computer applies them every time. The engineer's job moves from doing the repetition to designing the rule and checking the result.

The three kinds of automation

1. CAD automation (design automation)

CAD applications expose an API — a programming interface — that lets a program do what a user does with the mouse: open files, sketch, extrude, mate, dimension, generate drawings, export. SolidWorks has the SolidWorks API, Siemens NX has NX Open, CATIA has its automation interface, AutoCAD has the AutoCAD API. With them an engineer writes:

• Macros — short scripts inside the CAD tool (VBA in SolidWorks, journals in NX) for one-off jobs: rename features, batch-export PDFs, set every hole to one size.
• Configurators — a program that reads a table of sizes and generates a family of parts, assemblies and drawings.
• Add-ins — tools installed into the CAD application for a whole team: custom toolbars, property pages, company standards enforced automatically.

This is the automation closest to a design engineer's daily work and the fastest to learn, because the engineer already knows what the clicks do — the program just repeats them.

2. PLC and machine automation

A programmable logic controller runs the sequence of a machine: sensors in, actuators out, interlocks, timing. Mechanical engineers meet it when they design the machine the PLC controls — a special-purpose machine, a test rig, a conveyor cell. The skills are ladder logic or structured text, I/O wiring, and reading the machine's sequence as a state diagram.

3. Industrial automation systems

At plant level, automation ties machines together: robots, material handling, SCADA and MES software, data from every station. Here a mechanical engineer works alongside controls and software engineers on layout, throughput, fixtures and the mechanical side of robot cells. The skills are systems thinking, specifications and integration rather than one programming language.

Where it is used

• Product design: variant families, configurators, automatic drawing generation, standards checking.
• Manufacturing engineering: CAM and tool-path automation, fixture design families, machine programs generated from the CAD model.
• Plant and process: conveyors, packaging lines, assembly cells, test rigs.
• Quality and documentation: BOM and report export, revision control, batch conversions (STEP, PDF, DXF).

Which skill to learn first

For a mechanical engineer who designs in CAD, the highest-return first step is CAD automation on the software you already use, in this order:

1. Record and read a macro. Every CAD tool has a recorder; reading what it writes teaches the API's vocabulary in an afternoon.
2. Learn the object model. Document, feature, sketch, dimension — the same shape in SolidWorks, NX and CATIA. This is the part that transfers between platforms.
3. Move from macro to program. When a macro needs a form, a loop over a folder, or a colleague wants it on their toolbar, write it as a C# program or add-in.
4. Then widen: PLC basics if you build machines; data and integration if you work at plant level.

Programming experience is not a prerequisite. The language (VBA, then C#) is learned on the way; the engineering judgement about what to automate is the part you already have.

Learning it at ApiXpert

ApiXpert's courses follow exactly that path, platform by platform. The SolidWorks API & Automation Course starts with VBA macros and moves to C# add-ins; the NX Open API & Automation Course does the same for Siemens NX with journals and C#; CATIA and AutoCAD have their own paths. Each course is recorded or live with trainer support, and each starts with a short trial lesson so you can see the teaching style before you commit.

Frequently asked

Is automation replacing mechanical engineers? It replaces the repetitive part of the work. The engineer who can write the rule — and check the result — becomes more valuable, not less.

Do I need to be a programmer? No. Start with a macro recorder on your own CAD tool; the course teaches the language from the foundations.

CAD automation or PLC first? The one that matches your work. Design engineers: CAD automation. Machine builders: PLC. Both share the habit of writing the rule down once.