Hugo Troche's blog: Why aren't Workflow engines parts of almost every JEE application? The Missed Opportunity

Workflow Engines like jBPM from JBoss are the perfect tool to model any process that has many paths, and requires human involvement between process tasks. Let's just start thinking about some common applications:

- Shopping cart: It is a perfect fit for a workflow engine. Each step in the process of buying an item is well defined, each step requires human interaction and finally there are many paths in the process (a shopper can pick from a myriad of shipping options for example, each with its own distinct actions to follow).
- Recruiting website: A candidate needs to enter his/hers skills. The system then matches the candidate to a job and notifies a recruiter and the candidate. The candidate and the recruiter review the match. If there is common interest, both parties communicate and so on.

I can keep going on and on with application examples that are simple business process representations. If that is the case, why don't we use JBPM or similar frameworks more often? Why are we not fluent in BPEL? After all, a workflow engine provides us with so many advantages:

a) It saves the state of the process. If a shopper exits a website before finishing with the shopping cart, the engine will easily bring the back session exactly to the point where it was before the user exiting. Implementing that logic without a workflow engine is usually time consuming and error prone.

b) It provides with a clear separation between the business process definition and the process task itself. jBPM is so effective in abstracting the task from the process that a non developer can reorganize the tasks later on. Most of these tools also have GUIs to manage the business processes. Try implementing that from scratch.

c) It reduces the complexity of applications by leveraging the engine to do the "plumbing" work of the business process. The developer just needs to focus on the process tasks and the business analyst in the process.

There are many other reasons about why a workflow engine is such a great and fundamental component to almost any application. Yet, why aren't workflow engines more popular? These questions nagged me for a while. I think there are 3 main reasons why workflow engines are not more popular:

1) The learning curve to be proficient in any of these frameworks is high. Thanks to frameworks such as Spring, developers want tools that they can start using right away after reading a few tutorials. jBPM is no such tool. This by itself should not be a reason for the unpopularity of workflow engines, but combined with,

2) There is no dominant player in the market. The market is fragmented. Don't get me wrong, there are many standards that most players are using, yet the standards are too low level for the skills to translate between frameworks.

3) Workflow engines live in the murky grayness between developers and business analysts. Some of the commercial workflow engines are geared and sold to business analysts. While other engines like JBPM are more geared towards developers. The successful engine has to be able to address both concerns.

The workflow engine will start becoming the Rosetta Stone of modern enterprise systems. With the current SOAs Web Service access orchestration is already difficult. To take advantage of the long tail of possibilities in an SOA, a developer needs a solid way to model the business processes that access all those web services. Then, as the market moves towards ESBs, workflow engines and rule engines will be the glue of modern enterprise systems.

So, who will come up with the Spring of BPEL? How will come up with a powerful simple, open source framework that scales?