Data Warehousing Project - OLAP Cube/Report Design
Usually the design of the olap cube can be derived from the Requirement Gathering phase. More often than not, however, users have some idea on what they want, but it is difficult for them to specify the exact report / analysis they want to see. When this is the case, it is usually a good idea to include enough information so that they feel like they have gained something through the data warehouse, but not so much that it stretches the data warehouse scope by a mile. Remember that data warehousing is an iterative process - no one can ever meet all the requirements all at once.
1 - 2 weeks.
Make sure your olap cube-building process is optimized. It is common for the data warehouse to be on the bottom of the nightly batch load, and after the loading of the data warehouse, there usually isn't much time remaining for the olap cube to be refreshed. As a result, it is worthwhile to experiment with the olap cube generation paths to ensure optimal performance.