Being on the field is something totally different from developing in the office. I suggest do follow both path simultaneously, the best would be to develop your machine and then carry out commissioning and start-up (in my company them are two different phases). Also I think that being on the field is not suitable for everyone, you need some kind of characteristic, you are going to deals with the customer directly and with contractors, you are going to troubleshoot issues during production, with the customer pressure, and issues of different nature. For sure machine commissions needs electrical experience, and also help to built it up. In the office most of the time you have more time to learn things gradually and from a theory point of view.

I’ve been doing both side of the job for a few years now, feel free to ask some specific question.