Mapping to Business Execution Languages

Mapping to Business Execution Languages :
Business Process Modeling Languages are XML-based meta-languages used as a means of modeling business processes in an XML format. Many different Business Process Modeling languages have been proposed. Most of them use XML and build on top of the Web Service Description Language (WSDL) by the W3C standards body. A major flaw of WSDL is that the language mixes static interface description and binding information to certain communication protocols.
The new breed of Business Process Modeling Languages include the Business Process Execution Language for Web Services (BPEL4WS), created through a joint effort of BEA, IBM, and Microsoft, and the Business Process Modeling Language (BPML) created by BPMI.ORG.
Both of the standards provide specifications for:
• Dataflow
• Messages
• Events
• Business Rules
• Exceptions
• Transactions (Distributed, Compensating, Synchronous, Asynchronous)

BPMN Maps Directly to Execution Languages :
As mentioned in the introduction, BPMI has developed BPMN with a solid mathematical foundation – the Pi-Calculus branch of Process Calculi has been used. This is a formal method of computation that forms the foundation for dynamic and mobile processes. It means that business processes designed using the BPMN standard can be directly mapped to any business modeling executable languages for immediate execution. Again, this is analogous to the functionality of relational data models and the generation of SQL/DDL statements.

BPMS’s Orchestrate Web Services :
The internet is a heterogeneous environment of many different platforms and applications. In an end-to-end value chain, organizations and individuals want to pick best-of-breed components that provide the value chain with best value. The applications and services need to work together harmoniously. This is one of the driving forces for the standardization of web services.
As we mentioned at the beginning of this paper, making web services work is a four stage process – designing the processes with BPMN, verifying them for efficiency with simulation, making them available by publishing them using a business process execution language, and orchestrating and coordinating them using a Business Process Management System (BPMS).
BPMS’s offer the ability to transform the distinct disciplines of workflow, EAI, and B2B from a complex high-end solution practiced by a few highly skilled practitioner consultants into an open solution accessible to the masses of developers producing new types of agile, loosely coupled applications. BPMS’s orchestrate participants (applications, people, partners) into executable, end-to-end processes and close the gap between strategy and business execution.

How BPMN Fits In with UML :
The advent of BPMN, BPML’s, and BPMS’s does not render obsolete the need for systems development, such as that performed using the Unified Modeling Language (UML). Systems development still has an important role to play in the overall enterprise architecture process.
UML is a language that helps developers specify, visualize, and document models of software systems. It is very much targeted at system architects and software engineers. It has been developed as a means to streamline the software development process, from architecture design to application implementation for use by a technical audience.
BPMN is targeted at business analysts, system architects, and software engineers. It has been developed as a way to streamline the overall business lifecycle development process from process design – performed by a business audience.

UML Is Alien to Most Business Analysts :
1. Static application structure
2. Dynamic behavior
3. Management and organization of software solutions

Of these categories it is the dynamic behavior diagrams that are often used for modeling business processes, such as the UML Activity diagram and Use Case diagram. BPMN is related to UML in the sense that it defines a graphical notation for business processes that is similar to UML behavior diagrams. However, BPMN and UML have very different approaches to business process modeling.
UML offers an object-oriented approach to the modeling of applications, while BPMN takes a process-centric approach. Most UML methods ask you to find the objects first using static structure diagrams, and then ask you to build dynamic behavior diagrams to show how objects interact. As a way to model, this method is alien to most business analysts.
BPMN offers a process-centric approach that is more natural and intuitive for the business analyst to use. With BPMN, control and message flows of processes are modeled first. An object model for the process is defined implicitly rather than explicitly. BPMN also offers you the option of explicitly modeling business objects that may be exposed through business services in your process flows.

UML Lacks an Implementation View of Business Models :
UML is an assemblage of diagrams that are the results of the collective best practices of the various founding practitioners. Unfortunately, what this means is that the diagrams are an aggregation that have not been specifically designed to work with each other. As a consequence, developers can only model part of their applications with UML; the detailed implementation level is not covered. In contrast, BPMN defines a single type of diagram that has multiple views derived from the same underlying process execution meta-model. The natural result of this is that implementation in a business process execution language merely becomes another logical view of the process.

UML Lacks Mathematical Foundation to Map to BPEL’s :
Finally, UML does not define any execution meta-model for business processes modeled with it. Instead, any execution meta-model must be defined using Model Driven Architecture (MDA). BPMN is based on BPML’s process execution meta-model and so does not require any additional steps for the modeling fully executable processes.

BPMN and UML Play Together :

It is anticipated that BPMN and UML will co-exist. There will be technical users that do not intend to use BPML as the final means of deployment, who will continue to use UML. Figure 16 shows that BPMN can be used to drive solutions that will run directly on a BPMS or be used as a business analysis front-end for subsequent systems development using UML. In this scenario UML users would regard business processes merely as another type of componet.