The other day I heard Thomas Kurian talking about the future of the Oracle technology stack. Among other things, he mentioned the Oracle BPA Suite and the Oracle BPM Suite (fka BEA AquaLogic BPM). According to Thomas, the "structured" BPA Suite aims at rigorous process modeling and simulation, where the "agile" BPM Suite aims at iterative process modeling.
Methodological me tended to hear that he was saying that the BPA Suite was more suited for plan-based development, where the BPM Suite would better support agile development. Knowing both of these tools, I found that a somewhat rigorous statement by itself, so I dug into the subject somewhat more.
Yes, the Oracle BPA Suite has a huge amount of modelers and an astronomical amount of symbols. And yes, being able to use the tool to its full extend requires a learning curve that looks the inverse of the stock markets of these days. But does that mean you cannot use it in an agile way? Not really, because being agile is less about how long it takes to learn something, but more about being able to apply it to create new or change existing software.
On the other hand, would the Oracle BPM Suite not be suitable for rigorous process modeling and simulation? Again I don't see why. You could easily have a very rigorous way of developing systems with strict procedures to follow, including an extensive QA process and still use a tool like the BPM suite.
Maybe we need to have a look at the subject from a different angle. Let's start with a limited feature comparison. Limited in that I restrict it to a development environment based upon a SOA with a focus on the high level topics of the models that are supported, how Governance can be enforced, and the type of systems that you can build.
Models and Governance
In a nutshell, with the BPA Suite you can start by defining business processes from a high-level context diagram up to a detailed design. At the higher levels you can use Value (Added) Chain Diagrams, or VACD's for short, that at a specific point map on BPMN diagrams. Those BPMN diagrams can then be transformed into a BPEL design, which finally can be implemented using JDeveloper. The higher-level modeling can be done by Business Analysts while the detailed BPMN model typically will be done by someone with a developers background.
With the BPA Suite you can define roles and restrict access to specific modelers of the tool. This allows you to implement a rigorous Governance model you might have, where the responsibilities for the different roles are well supported by the tooling.
With the BPM Suite you can define processes using BPMN (or similar notation, each being just another view on the same source). Next to that three different "profiles" are supported: Business Analyst, Business Architect, and Developer. The only difference being that a Business Analysts sees the least and a Developer the most details of the same process.
Unless you start doing really fancy things, the BPM Suite does not support a rigorous Governance model as far as responsibilities are concerned, as nothing prevents a Business Analyst from changing his profile to developer to see what has been coded under the hood and even change that.
So the BPA Suite supports a rigorous enforcement of Governance and capturing of requirements, where the Suite BPM supports that hardly if at all. But as such I don't want to call that an "agile" aspect of the BPM Suite.
Regarding Governance, there is one other significant difference. The BPA Suite itself does not result in an executable model. BPMN can be transformed to BPEL, but that is only a blueprint. After sharing the blueprint with development (as it called), a developer picks up the BPEL blueprint and implements it.
The BPM Suite leverages XPDL which provides a means to draw business process models, but also is an executable model. So for the BPA Suite you could say there is a strict hand-over from design to implementation, where with the BPM Suite there is no such thing.
Type of Systems
Currently the BPM Suite clearly is coupled to BPEL. In our practice BPEL is heavily used to integrate systems, with little to no human workflow involved. But that does not mean that you cannot use it for processes that almost completely involve human interaction, and in practice it probably will.
Although at first sight the BPM Suite primarily seems to target processes that involve human interaction, nothing will keep you from developing processes that are fully automated. BPM processes can be deployed as services with a WSDL interface, and call other services, allowing it to be used for service orchestration only.
My conclusion is that regarding the type of system you can build, there is not really a significant difference between the two. Although with the BPM Suite it is much easier to create a user interface than with the BPEL human workflow. But are processes with a lot of human interaction agile and processes that are not rigorous?
When talking about rigorous versus agile and iterative, the significant difference I see is that with BPM it is hard if not impossible to build a solid wall between analysts and developers. And yes, it is true that agile development methodologies do promote breaking down that wall wherever possible.
By the way did I already say sorry for the lack of pictures this time? No? Sorry!