Feasibility metrics on the cheap

I'd like to track the customer's activities during the week to establish whether the problem I am solving is a minor annoyance or a big pain.

My full-time job makes it difficult to do the measurement myself so I plan on asking the end-user (I don't yet have access to the prospect) to jot down notes throughout the day. I need to know the start/end time for each "painful" event. For example, if my solution saves cashiers time by giving out exact change automatically (Subways does this) then I'd ask cashiers to note how often and long (start/end time) it takes them to dish out change. The more time they waste handing out change, the more time/money my solution could save them.

I am automating "offline" processes. Most of the events we will be measuring do not involve computers. For example, I might ask a Subways employee how long they spend taking down phone orders (in the hopes of computerizing the process) and currently they don't have access to a computer while doing this.

What's the best way to collect feasibility metrics on the cheap? Who should collect this information? What information should be collected?

In order for this real world research to be sound, I would say that you would require raw data that can be interpreted. Having spent some time in the retail industry myself, I would not trust data that is generated by employees.

Something funny starts happening when you ask them to monitor how long it takes them to dish out change. For example, they wont admit it but would change their pattern and try to be quicker or even slower depending on what they think you want to see.

When I use to make improvements in the region that I managed, I would literally go and sit in the security booth and observe for hours. Its amazing what you see when nobody thinks that you are watching.

For example:
Suddenly it becomes ok to sit and have the last piece of cheesecake and write on a note that it had to waste because it fell on the floor.

Thus, see if you can get actual real life footage that you can study, along with this organise that you can interview various employees on past events only when you have gathered enough relevant information on what you need. Otherwise this will create an atmosphere where they know that they are being watched and will change their bad habits. This will not reflect actual real life, and most likely not be in your favor.

Along with this, I would do a qualitative study that is confirmed with a quantitative study of the experience that your customers customers are having.

Something simple, like surveymonkey would work fine. Create a survey that probes specifically in the area that you are interested in.

If you really want to get the best and actual results, don't make it obvious that you are probing about receiving correct change. Ask questions about service, quality, etc and about getting change.

You will through this be able to see a pattern evolve, people complaining about certain dishes taking long, may also be complaining about long ques, etc.

Along with this, ask them to rate specific elements that has a direct reference to your service and make this both quantitative as well as qualitative.

For the best unbiased results, use open questions that does not lead the individual to an answer.

Hope this helps, Good luck with your research and hope it confirms your hypothesis.