Ed, We use both in our shop today for different customers (along with some other scheduling packages, too). They are quite different. TWS (formerly OPC) is very much in a class by itself on a number of points. In ESP, the majority of the definitions are handled via Rexx-based logic in the JOBPROC members. A lot of flexibility. TWS is extremely rigid by comparison. Everything is nested in layers and layers of online panels. The way the schedules actually process are polar opposites. ESP is driven by dynamic events. TWS has a layered approach of the application definitions, long term plans and current plans, the different plan phases managed by batch-loaded scans. That's just a high-level look at a few of the top items. From there you can go deeper. Even from what I hit, there are variations and other functionalities. We'd go on forever. I'm not saying one is good or bad. It's a matter of need. Some environments need a very strict and structured architecture to handle processing, others do better handled in a more free-form manner. From a purely personal standpoint, if I were dealing with a choice situation and had to pick between ESP and TWS, I'd go with ESP. My overall top preference is with one of the other schedulers we use here, but ESP is still up there on the list - #2 or #3, depending on what day you ask me. TWS is lower for us, but again, it depends on what you're needing to do. In our shop right now we use five different mainframe scheduling tools, including ESP and TWS. Of course, we have the impossible dream of wishing someone could take all the features we like best and come up with some hybrid super-scheduler that catches it all and eliminates all the stuff we don't want. Never gonna happen, but it's nice to dream. Eric