Hi, I'm Stephen Atwell, the product Manager who owns performance of the R12 platform. This is an area we are continuing to look at, and continuously improve. Here are some things you my find helpful off the various comments.
1) In general, for the vast majority of our customers the performance of TBMAs making configuration changes is vastly improved over r11. This is an area we continue to look at, and there are still things that can happen in configurations that cause slowness. The main improvement in r12 here is impacts of multiple TBMAs on each other. The R12 architecture was built specifically to decrease impact of multiple TBMAs. If you have unacceptable performance in dev, reach out to support or your CSM and they should be able to help.
If the slowness is primarily experienced only when a large number of TBMAs are logged into the system, R12 does support spreading multiple TBMAs out over multiple dedicated compute resource to further decrease their impact upon each other. This is currently manually configurable by Apptio if you contact support, but it is on our roadmap to make it automatic.
2) Dev calculations are a concept that exists in R12 that does not exist in R11. These calculations run basic validations, and prevent one TBMA from seeing another TBMA's changes, or modifying the same portion of the configuration as another TBMA until after they complete. Apptio is investigating optimizations that can decrease dev calculation times further.
3) Real-time performance: In general this is much better than in r11, HOWEVER there have been, and will continue to be optimizations in this area. One noticeable improvement is that prior to 12.5 expanding a report collection or table group within TBM studio would tend to take many seconds. The query that caused this was optimized, and if this is affecting your TBMA experience, upgrading to the latest GA release will likely help significantly.
4) Multi-object reporting does have additional calculation and reponse time improvements coming out in the 12.6 timeframe. However, 3+ object reporting performance, and 2+ object reporting performance when doing time aggregation (yearToDate, Annual, etc) will continue to have performance challenges for some configurations for the near term future. There are bigger ticket roadmap items we are looking at that should improve these.
Performance is something that Apptio takes seriously. We are continuously optimizing the platform, and fixing the performance issues that affect the widest groups of customers. The best way to improve your performance is typically to upgrade to the latest GA release of the Apptio platform.
Hope this helps!