Business Process Management and SOA
One of the major benefits of a Service-Oriented Architecture is its ability to align IT with business processes. Business processes are important because they define the way business activities are performed. Business processes change as the company evolves and improves its operations. They also change in order to make the company more competitive.
Today, IT is an essential part of business operations. Companies are simply unable to do business without IT support. However, this places a high level of responsibility on IT. An important part of this responsibility is the ability of IT to react to changes in a quick and efficient manner. Ideally, IT must instantly respond to business process changes.
In most cases, however, IT is not flexible enough to adapt application architecture to the changes in business processes quickly. Software developers require time to modify application behavior. In the meantime, the company is stuck with old processes. In a highly competitive marketplace such delays are dangerous, and the threat is exacerbated by a reliance on traditional software development to make quick changes within an increasingly complex IT architecture.
The major problem with traditional approaches to software development is the huge semantic gap between IT and the process models. The traditional approach to software development has been focused on functionalities rather than on end-to-end support for business processes. It usually requires the definition of use cases, sequence diagrams, class diagrams, and other artifacts, which bring us to the actual code in a programming language such as Java, C#, C++, and so on. SOA reduces the semantic gap by introducing a development model that aligns the IT development cycle with the business process lifecycle. In SOA, business processes can be executed directly and integrated with existing applications through services.
To understand this better, let’s look at the four phases of the SOA lifecycle:
- Process modeling: This is the phase in which process analysts work with process owners to analyze the business process and define the process model. They define the activity flow, information flow, roles, and business documents. They also define business policies and constraints, business rules, and performance measures. Performance measures are often called Key Performance Indicators (KPIs). Examples of KPIs include activity turnaround time, activity cost, and so on. Usually Business Process Modeling Notation (BPMN) is used in this phase.
- Process implementation: This is the phase in which developers work with process analysts to implement the business process, with the objective of providing end-to-end support for the process. In an SOA approach, the process implementation phase includes process implementation with the Business Process Execution Language (BPEL) and process decomposition to the services, implementation or reuse of services, and integration.
- Process execution and control: This is the actual execution phase, in which the process participants execute various activities of the process. In the end-to-end support for business processes, it is very important that IT drives the process and directs process participants to execute activities, and not vice versa, where the actual process drivers are employees. In SOA, processes execute on a process server. Process control is an important part of this phase, during which process supervisors or process managers control whether the process is executing optimally. If delays occur, exceptions arise, resources are unavailable, or other problems develop, process supervisors or managers can take corrective actions.
- Process monitoring and optimization: This is the phase in which process owners monitor the KPIs of the process using Business Activity Monitoring (BAM). Process analysts, process owners, process supervisors, and key users examine the process and analyze the KPIs while taking into account changing business conditions. They examine business issues and make optimizations to the business process.
The following figure shows how a process enters this cycle, and goes through the various stages:
Once optimizations have been identified and selected, the process returns to the modeling phase, where optimizations are applied. Then the process is re-implemented and the whole lifecycle is repeated. This is referred to as an iterative-incremental lifecycle, because the process is improved at each stage.
Organizational aspects of SOA development
SOA development, as described in the previous section, differs considerably from traditional development. SOA development is process-centric and keeps the modeler and the developer focused on the business process and on end-to-end support for the process, thereby efficiently reducing the gap between business and IT.
The success of the SOA development cycle relies on correct process modeling. Only when processes are modeled in detail can we develop end-to-end support that will work. Exceptional process fl ows also have to be considered. This can be a difficult task, one that is beyond the scope of the IT department (particularly when viewed from the traditional perspective).
To make process-centric SOA projects successful, some organizational changes are required. Business users with a good understanding of the process must be motivated to actively participate in the process modeling. Their active participation must not be taken for granted, lest they find other work “more useful,” particularly if they do not see the added value of process modeling. Therefore, a concise explanation as to why process modeling makes sense can be a very valuable time investment.
A good strategy is to gain top management support. It makes enormous sense to explain two key factors to top management—first, why a process centric approach and end-to-end support for processes makes sense, and second, why the IT department cannot successfully complete the task without the participation of business users. Usually top management will understand the situation rather quickly and will instruct business users to participate.
Obviously, the proposed process-centric development approach must become an ongoing activity. This will require the formalization of certain organizational structures. Otherwise, it will be necessary to seek approval for each and every project. We have already seen that the proposed approach outgrows the organizational limits of the IT department. Many organizations establish a BPM/SOA Competency Center, which includes business users and all the other profiles required for SOA development. This also includes the process analyst, process implementation, service development, and presentation layer groups, as well as SOA governance.
Perhaps the greatest responsibility of SOA development is to orchestrate the aforementioned groups so that they work towards a common goal. This is the responsibility of the project manager, who must work in close connection with the governance group. Only in this way can SOA development be successful, both in the short term (developing end-to-end applications for business processes), and in the long term (developing a fl exible, agile IT architecture that is aligned with business needs).
Technology aspects of SOA development
SOA introduces technologies and languages that enable the SOA development approach. Particularly important is BPMN, which is used for business process modeling, and BPEL, which is used for business process execution.
BPMN is the key technology for process modeling. The process analyst group must have in-depth knowledge of BPMN and process modeling concepts. When modeling processes for SOA, they must be modeled in detail. Using SOA, we model business processes with the objective of implementing them in BPEL and executing them on the process server. Process models can be made executable only if all the relevant information is captured that is needed for the actual execution. We must identify individual activities that are atomic from the perspective of the execution. We must model exceptional scenarios too. Exceptional scenarios define how the process behaves when something goes wrong—and in the real world, business processes can and do go wrong. We must model how to react to exceptional situations and how to recover appropriately.
Next, we automate the process. This requires mapping of the BPMN process model into the executable representation in BPEL. This is the responsibility of the process implementation group. BPMN can be converted to BPEL almost automatically and vice versa, which guarantees that the process map is always in sync with the executable code. However, the executable BPEL process also has to be connected with the business services. Each process activity is connected with the corresponding business service. Business services are responsible for fulfilling the individual process activities.
SOA development is most efficient if you have a portfolio of business services that can be reused, and which includes lower-level and intermediate technical services. Business services can be developed from scratch, exposed from existing systems, or outsourced. This task is the responsibility of the service development group. In theory, it makes sense for the service development group to first develop all business services. Only then would the process implementation group start to compose those services into the process. However, in the real world this is often not the case, because you will probably not have the luxury of time to develop the services first and only then start the processes. And even if you do have enough time, it would be difficult to know which business services will be required by processes. Therefore, both groups usually work in parallel, which is a great challenge. It requires interaction between them and strict, concise supervision of the SOA governance group and the project manager; otherwise, the results of both groups (the process implementation group and the service development group) will be incompatible.
Once you have successfully implemented the process, it can be deployed on the process server. In addition to executing processes, a process server provides other valuable information, including a process audit trail, lists of successfully completed processes, and a list of terminated or failed processes. This information is helpful in controlling the process execution and in taking any necessary corrective measures. The services and processes communicate using the Enterprise Service Bus (ESB). The services and processes are registered in the UDDI-compliant service registry. Another part of the architecture is the rule engine, which serves as a central place for business rules. For processes with human tasks, user interaction is obviously important, and is connected to identity management.
The SOA platform also provides BAM. BAM helps to measure the key performance indicators of the process, and provides valuable data that can be used to optimize processes. The ultimate goal of each BAM user is to optimize process execution, to improve process efficiency, and to sense and react to important events.
BAM ensures that we start optimizing processes where it makes most sense. Traditionally, process optimization has been based on simulation results, or even worse, by guessing where bottlenecks might be. BAM, on the other hand, gives more reliable and accurate data, which leads to better decisions about where to start with optimizations. The following figure illustrates the SOA layers: