Reporting against OLTP - urgent

I have a set of reports that are going against OLTP systems since the requirement is for real time data reporting. There is a request to improve performance.
Could you suggest ways to do so, data warehouse is not an option. Is ODS better? what are the pros and cons?
Is it recommended to build cubes on top of OLTP?

DW is not an option, yet every option you propose involves moving the data out of the OLTP system. If you do that, going to the DW is just as valid as others you mention.

The issue is what does the business mean by 'real time'? What level of data latency is acceptable? What level of latency that you do experience will be more an issue of how you can detect change in your source system rather than the choice of target system (although loading a cube would probably be the worst choice in that respect).

If you have to use the OLTP system, then there are several performance tuning options available. Partitioning, denormalization, and derived tables and or columns, are several techniques. It really sounds like management needs to get a clue though. You can't have your cake and eat it too.