We have a very large, multi-year program with many projects. We are using MS Project as a scheduling tool. The Master-Sub functionality in Clarity is limited and performance unacceptable for our master schedulers so they have discontinued using them. Each of the projects within the program has a very large schedule (5,000 + tasks) with 200+ resources assigned to tasks and reporting actuals in Clarity. Without an efficient means to level resources across multiple projects in MS Project they use pivot tables in Excel. Are others using Master-Subs with MS Project on very large projects with hundreds of resources?