It's tempting to just get coding and respond to verbal requests for additions and improvements, leading to confusion, time, and cost overruns. Avoid the temptation and stay in control.
QlikView is a great tool for iterative development, but it's important to keep track of user requests. Agile development with regular sprints works well for QlikView developments, but the content of each sprint needs to be documented and communicated to your users. It is rare to see large, detailed specifications in QlikView projects. Most requests amount to no more than half a page of text and are often just verbal. Hence, it is necessary to keep track of every enhancement request, problem, and bug, allocating them to sprints as dictated by importance, difficulty, and time required.
The most important thing to remember is that, if there's no release discipline with a clear schedule, you will never finish the development. Iterative development means that the user is involved on a regular basis and will always ask for 'just one more thing'. All this will prevent you from drawing a line under each development phase unless you are very clear about development phases and their timings.
There are two ways to approach this problem: either you give the user a list of all the items that will be in a release and provide no more than that list, or you timebox the development. Timeboxing means that you start with a list of requirements and priorities, but agree on a period of time in which to do them. If they aren't all done in time, they don't go into the release. Either of these approaches works well with QlikView developments.
Keep track of every change request—even the most trivial ones. This way, you'll be able to tell all your users at once when the request is complete. If you make a simple change while talking with a user or just because it seems like a good idea, you'll either have other users asking when the change will be made or expressing surprise that you have made the change.
Be very clear about what will and won't be in each release. If you use timeboxing for development, your users need to understand that they won't necessarily get everything they expect in each release. Your release notices should itemize what is and isn't in the release.
Depending on how formal your working environment is, you may also need an agreement from a senior user or steering group as to what is to be done. It's also quite likely that they will want to sign off any change before it is actually released to production. The larger the company or project, the greater the chances are that you'll have to comply with these arrangements.
You also need to consider exactly what release means in your situation. It could be a release to test, in which case you will concurrently run the test and production releases, and the test release will be the next production release. This requires more careful management as any fixes in the test release would need to be applied to the development release. Alternatively, you might release to test a couple of days before the scheduled release to production, giving the users a little time to test and very little time for any remedial work. This approach means, at the least, that you have only one release at a time to worry about.
Many enterprise environments will most likely have some sort of change management or request tracking system already in place, but it's surprising how many don't. Very large developments may even justify being managed in something similar to Microsoft Project, but this isn't really the right tool for detailed requests. You could, of course, use it to manage your release schedule or a larger ongoing project.
If your project doesn't have a change management or tracking system, create one of your own. It doesn't need to be overly complicated; a spreadsheet will do. Basically, you need to keep a list of requests, snags, and bugs. Note who reported or requested the item and when it was reported, the nature of the issue and who owns the issue, the priority or severity of the issue, its progress, outcome, and outcome date (or release), and who completed the task. From this, you can keep track of every item.
Even a simple tracking system is better than no tracking system at all. Don't rely on e-mails and water cooler conversations; log everything in your tracking system. If it isn't in the tracking system, it doesn't happen.
You could even create a small QlikView application that uses your spreadsheet to allow management to see how productive you have been!