A friend of mine had been working in a company for some time, and she wants to include it in her resume to apply for another job. The thing about it is, one of her duties in that company was to inspect new machines they received, but in reality during her time in the company they didn't actually receive new equipment so she didn't actually got to do that duty. She wants to know whether she should include it or not, and how would she go about it. Maybe add a little title that explains it, or say these were the job duties regardless of what she has actually done?
Your CV should be positive, truthful, and not misleading.
I would say for example "My responsibilities included X, Y, Z, but Y was never actually required during my employment".
This shows that your previous employer trusted you to do Y if it was needed, but that you don't actually have much practical experience in it. Which is better than not mentioning Y, but still truthful.
She was assigned the job duty so they felt she would perform the task. Did she receive any special training? If she received no special training then it is probably best to leave it off.
I was on emergency fire crew at a refinery and never fought a fire. I would have put that on my resume if I was looking for a job at the time. But I did receive training in fire fighting.
Extending on the above comments (which I've all +1'd), as a hiring manager I can say with absolute confidence that if I discover during an interview process that a candidate has a skillset on their resume where I find out that they really have no experience in it*, the candidate's chances of getting the job end right there, as it goes against honesty and makes me wonder what else the candidate has lied about.
Also if the candidate was represented by an agency I will now question that agency's honesty, which may impact whether I want to do business with them again.
*This also includes grey areas like 'I took a one-day class in it', 'We talked about it once', 'I know how to spell Java therefore I have those skills', you get the idea.
It's a huge risk to include something that you haven't really done.
For one, the lack of experience can show when you are assigned to work on it. This could seem to the employer that you are really inefficient at what you did at your previous workplace. It could also end up affecting your future prospects at your workplace.
The better thing is to state the work you did and mention that you are willing to learn the new trade in case your job requries it.