You're looking at a manufacturing company? That should be easy because you directly relate output and quality before and after. You could even say that because of the nature of the company you decided to explore this aspect for your IA (rather than finance, marketing, etc).
The point about the IA is not to see results. You're not going to write this over a 3 month period and examine whether your motivation techniques actually do increase motivation, productivity etc. You need to look at the company now, how it is, and decide on a topic you could investigate.
The classic example I think teachers and IB always say is "should company X by a new photocopier". Its small, its precise, focuses on 1 aspect (finance), and you can write in depth about it as you have 2000 words.
So your question could be like "Should company X employ motivational techniques to increase output" or what ever. You could briefly state what you've learned in class and through independent research as your secondary research (i.e. various motivation theorys like maslow's hierarchy or herzberg's two factor theory and how the research shows that these motivate people). Then do some primary research. Ask the boss if they've thought about this, or what they do to motivate employs or increase productivty. You may find that you can write something like "Currently company X employs several motivation techniques such as bonuses, but other techniques such as ... may have more of an effect". Then follow through with interviews with employees. Do they feel motivated? How would they like to be motivated? What would motivate them?
And then in your conclusion you could say "Company X should employ motivation techniques" and recommend specific techniques. "The interviews conducted with employees shows that they would find these techniques effective". Something to that effect I guess.