As i understand correctly, BPM suite is to design processes around people, systems and documents. It will consist of tasks which will require Human interventions. BPA on the other hand is for designing/executing fully automated process (least or no stoppages) and is required by business implementing Six Sigma or likewise initiatives.
Oracle BPA Suite is a tool that is very suitable for enterprise wide business process modeling and enterprise architecture. It allows you to model your organization, strategy and processes.
This is useful when defining strategy, or to comply with laws that require you to model your business processes. It offers dependency matrices between different diagram types, simulation, definition of KPI's etc etc.
You can model automated processes, manual processes etc.
If you want to actually execute a process model that you defined in Oracle BPA you can choose to execute that model in either BPM Suite (BPMN) or SOA Suite (BPEL). You hand over the lowest level of process model to IT, who will use these tools to add implementation details.
BPM suite has a number of features that are available in BPA Suite as well, like simulation. But it is totallly focussed at the project at hand, not at your total enterprise.
To summarize: your architects and business analysts can use BPA Suite to model as-is and to-be situations. When you focus on the implementation of one business process, BPM Suite is your tool.
Thanks - that explains!
For a strategic/pre-implementation work like as-is, to-be, gaps, requirements definition, etc. BPA works best - and for tactical/implementation of the requirements/processes, BPM works best!
The analyst view in BPM has capabilities to model a specific business process using BPMN 2.0 modeling notation, so yes, there are some similarities, however BPA is really focused on higher level, enterprise wide modeling that might be done using rigorous methodologies. BPA allows you to model a specific process, like BPM but the power of BPA lies in its ability to model other things that relate to processes, like Systems, data, people and organisations and services, this is a wider set of models that represent the 'enterprise'. A set of models that relate not only to processes, but other parts of the enterprise. BPA allows you also to understand the relationships and impact of change between the models, so, for example, if a strategic objective of a company was modeled, you could see its impact of the processes, people and systems affected by that objective.
Plus, BPA Suite supports many different notations for modeling (UML, EPC, BPMN...) while BPM 11g only supports one (BPMN).
BPM11g now has the web based modeler (BPM Composer) which requires no desktop install for Business Analysts, just point the browser to the BPM Composer and voila. and it's read/write.