18days is a very big deal. I suggest you to try the direct discovery concept of Qlikview i.e no need to load all the data to in-memory instead bring only a required set and rest take it on fly.
Check with this link.
To reduce the reload time, try like this:
1.Instead of pulling all the data, pull only the required fields.
2.Do all the aggregation and store only necessary set of data.
3.If it taking so long time then divide the task between multiple qvw's that one to generate sales, one to organisation ,other etc