18 May 1996 updated
Here are my thoughts comparing Bachman and PowerDesigner products: (Within the notes are suggested improvements to PowerDesigner)
Bachman is new to Windows, having ported the products from OS/2 directly. PowerDesigner has been on Windows since the beginning and you can tell when using the product. (performance, printing, reporting, ease of use, stability etc etc)
Interactive "Expert Advisor" for Bachman is a plus, as it guides you interactively through checking the models for accuracy and completeness. The separation of Logical and Physical Models with synchronization through "maps" is a strong Bachman distinguisher. PowerDesigner has this capability, but does not provide a "map" object for cross-referencing logical objects to physical but does have limited capability with Name and Code.
Synchronization, however, is complex and can be error prone with Bachman tools. Reporting in Bachman is good with an external Reporting tool based on Microsoft Access. PowerDesigner would do well with such a product so that end users can run their own reports/queries from the Dictionary, for instance.
Bachman also has a "N aming Standards" utility which allows consistent translation of Logical to Physical names according to a customizable lexicon. e.g. customer is always translated to CST.
Bachman supports "Complex relationships" e.g. AND, OR, XOR etc, in an easy to follow diagramming style, and also supports Super/Subtyping with a very popular "Box-in-Box" notation. However, PowerDesigner provides more flexibility when generating a Physical model from these "Entity Type Hierarchies".
Bachman PM is based on Gane and Sarson conventions (single plane diagram). Almost everyone wants Yourdon/De Marco or equivalent with leveling diagrams (PowerDesigner Process Analyst). Bachman does not provide this and that is a big objection. The integration of Process Model and Data Model is very good, however.
Event Modeling and State Transition Diagrams are standard requests from customers, that Bachman has not provided yet. PowerDesigner futures on Event modeling/STDs?
Bachman's current offering of Shared Work Manager is based on a proprietary database. The non-proprietary Dictionary is a good distinguisher for PowerDesigner, but the solution needs completion with full "round-trip" processing including full security specifications. There have been requests for a real-time centralized dictionary, to eliminate the need for Extraction/Consolidation processes. However, the trade-off is performance.
Bachman products are expensive when you add up the cost of all of the necessary modules. e.g. to perform logical and physical modeling you require GroundWorks, Terrain and TerrainMap with extra options for SQL/Server or Oracle generation.
Bachman can reverse engineer up to the logical level but so can PowerDesigner with Generate CDM. Bachman can do this incrementally, but requires great knowledge of the product and introduces great complexity. The Bachman Terrain product's Meta model is based on the SQLServer Catalog so is fully functional for that database (and supports ALL Sybase objects), but therefore provides support for Oracle and other ODBC databases through "Sybase sunglasses".
The mapping of datatypes from logical to physical is fixed with Bachman but, as I understand it, you may choose to modify the translation with the PowerDesigner .DEF file. This is a better approach, I feel, adding flexibility. Again, dedicated development for Sybase by Bachman, provides good support for that DBMS but partial support for other databases.
PowerDesigner's tighter integration with PB and 4GL's is important. The AppModeler release of PowerDesigner provides great added value in the form of working first-cut applications/prototypes.
Large model management is a Bachman strength, but mainly provides success through consulting services. The tools tend to have a high learning curve. The Bachman Meta model is publishedbut is stored in a proprietary relational engine. You can extract it to MS Access or DB2/2 for reporting purposes. PowerDesigner is much more intuitive and easy to use. The non-proprietary PowerDesigner Dictionary is a plus.
PowerDesigner will grow rapidly due to the stamp of approval from Powersoft and Sybase, agreed. Bachman's products are mature.
Bachman products are sophisticated and deep with functionality. Therefore they command a higher price point. But they are difficult to learn and can be extremely complex to use. From my tests, PowerDesigner provides almost all of the functionality for a fraction of the price with added value in the external Dictionary and integration with 4GL's. The backing of Powersoft and Sybase will be a huge advantage for PowerDesigner.