Click here to close now.


Microservices Expo Authors: Pat Romanski, Liz McMillan, Carmen Gonzalez, Jason Bloomberg, Tim Hinds

Related Topics: Microservices Expo, Industrial IoT

Microservices Expo: Article

Process-Centric Realization of SOA

BPEL Moves Into the Limelight

Agile and adaptive business processes and supporting IT infrastructure are the holy grail of enterprise applications. The industry is heading in the right direction to start delivering on this promise. SOAs (service-oriented architectures) promise to enable businesses to align their business processes to customer needs, and optimize them to improve customer responsiveness and drive efficiency. A process-oriented realization of SOAs is necessary to deliver on this promise.

The process-oriented model is based on an SOA component model augmented with an underlying formal model in which business processes are expressed through orchestration and choreography. This model blends the bottom-up framework of SOA with a top-down, process-centric view. By simplifying the set of activities that are part of the life cycle of business processes, we'll outline how this approach is an effective and efficient way to develop, maintain, and improve best-in-class inter- and intra-enterprise business processes. We'll also emphasize that enterprises looking to automate their business processes around an agile platform can start building, service-enabling, deploying, securing, and managing services - both internal and external - with Business Process Execution Language for Web Services (BPEL4WS or BPEL) business flows today.

The SOA Promise
Traditionally, business information systems have been developed with a functional orientation, often resulting in silos of services and information. However, end-to-end business processes that must span silos can't adapt to change as business needs evolve - they're fragmented and embedded deep within systems. SOA is a software architecture that facilitates the development of enterprise applications as modular and loosely coupled business services.

SOA's intent is to integrate software components, or services, in new runtime contexts and business processes. It creates a unification layer on which business processes and enterprise dashboards can be built. SOA promises to deliver greater responsiveness to business change and provide real-time visibility into business processes. When effectively implemented, it improves business agility by letting you modularize legacy, packaged, and custom applications, and orchestrate them in easily changeable business flows.

The Web services platform, including SOAP and other protocols accessed through Web services binding frameworks, acts as the component model and ubiquitous network fabric through which newly built and existing applications cooperate. Information can be exchanged much more seamlessly, unconstrained by the hardware, operating systems platforms, and programming languages used to implement services.

Whereas a Web services model and SOA often take an essentially bottom-up view, business processes are inherently top-down activities. Bridging the capabilities envisioned by SOA with the requirements of supporting distributed business processes - including trading partner collaborations - is the focus of the process-oriented realization of SOA discussed here.

SOA Realization
The process-centric realization of SOA can provide the glue between modular business services for the end-to-end business processes that companies rely on, such as order-to-cash, procure-to-pay, store order-to-sales compensation, and supplier-invoice to settlement. To complete this picture you must define all forms of business processes, including those of a collaborative nature, and deliver these processes reliably so that they, in turn, can be leveraged by other business processes and services (see Figure 1)

Today, mature standards such as BPEL and Web services effectively enable businesses to implement private processes and collaborative processes based on ad hoc collaboration definitions. The process-centric model of SOA considers processes and collaborations as first-class citizens, much as an object-oriented language would consider objects as first-class citizens, and encourages the same maturity of global standards for the definition of B2B processes. With this vision, business processes, collaborations, information exchanges, and work activities are expressed through service aggregation - a combination of BPEL orchestration and WS-CDL choreography, with operational semantics based on the pi-calculus:

  • BPEL orchestration is concerned with process-flow coordination and implements the behavior of a single participant/ business entity. For example, consider an order-to-cash that implements a business process that handles orders. Orchestration defines the execution logic of application components. Typically, a controller executes a definition of the business process. Standards have tackled process-flow coordination over the years, with the most recent industry consensus occurring around Web services orchestration standards like BPEL. BPEL is used to define the coordination of a process flow as well as related semantics, including parallelism, sophisticated exception handling, data transformation, and transaction compensation facilities.

  • WS-CDL choreography is concerned with multiparticipant collaborations, such as the Order Fulfillment collaboration between a buyer and a seller. The Web Services Choreography Description Language (WS-CDL) standard is emerging as a way to specify contracts of interoperable business processes collaborating to accomplish a common business goal. Examples of the business protocols that can be easily modeled using WS-CDL are the FIX and TWIST financial protocols and the RosettaNet PIPs. Choreography is built on top of BPEL. BPEL and WS-CDL together can express any business process, including trading partner interactions.

    In order to deliver quality of service to enterprise-class business processes a number of supporting services are required. With quality of service, a number of supporting services are required. These include security, reliable messaging, transactions, context and coordination, message translation and transformation services, message validation, and content-based routing. Although these services are vital for the vision of networked-enabled business processes, we'll focus on the service aggregation/business process aspects.

    BPEL: Automating Business Processes
    In the SOA architecture, and within the Web services platform in particular, services must be combined into business processes/business flows. BPEL provides a standard, portable language for coordinating the flow of business process services and builds upon a decade of progress in the areas of business process management, workflow, and integration technologies. Traditionally, such technologies have suffered from proprietary business processes definitions; the resulting applications are seldom portable across implementations, and skills are not transferable. Since BPEL is a standard, it creates a common language for developers. It's built from the ground up around XML and Web services and is supported on both the .NET and Java platforms.

    Asynchrony, parallelism, sophisticated exception handling, long-running processes, and a need for compensating transactions change the fundamental nature of what we think of as an application. In order to support the required executable behavior, BPEL provides constructs for control-flow (conditionals, sequencing, parallelism, loops), variables, and constructs for manipulating them; event handlers, timeouts, exceptions, and forward recovery; and nested scoping units of work.

    The process-oriented realization of BPEL also adds the following capabilities on top of standard BPEL:

    • Advanced data handling and transformation activities that are used to manipulate variables using XQuery
    • Advanced process life-cycle management capabilities such as versioning, Suspend Process instance, and Resume Process instance
    • Activities that use a business rules framework, which lets you model business rules in a purely declarative way
    • Advanced human workflow activities such as assigning tasks to specific users, sending notifications, and approving requests through mechanisms such as task lists
    BPEL provides the basis for implementing enterprise-wide business processes by combining existing business applications, custom applications, packaged applications, non-native services, and partner services into end-to-end business flows.

    WS-CDL: Collaborations Between Peer-to-Peer Business Processes
    In complex integration scenarios, capturing the collaborations between two or more business processes engaging in peer-to-peer business transactions, potentially across trust boundaries, requires a higher-level model. This is the fundamental thrust of WS-CDL, which is based on a variant of pi-calculus. It enables the formal modeling of the common observable behavior of all collaborating participants from a global viewpoint.

    WS-CDL describes the global message exchange of participants during their joint interaction, global reactive rules for declaratively prescribing normal/abnormal progress, common agreement of the outcomes, and a recursive composition model that lets you build choreographies incrementally by combining existing choreographies. In this way, complex inter-organization business processes can be implemented as a collection of services, which, in turn, implement complex business processes themselves.

    Choreography perfectly complements the effort of orchestration and BPEL, offering a global viewpoint into the peer-to-peer interacting business processes that are defined and implemented in BPEL.

    To understand how orchestration and choreography come together, let's consider an example.

    Case Study: Order Management Business Process
    For any business interaction to work, the rules of collaboration must first be agreed upon. These rules can be represented in English. However, since English is unstructured and frequently vague, the rules may not be represented precisely. Choreography, and WS-CDL in particular, lets us write the above rules in a precise and unambiguous manner. So how do orchestration and choreography fit into the larger picture? The case study below demonstrates their complementary role by presenting the example of a localized business process that's concerned with handling purchase orders in a really big corporation (RBC).

    This business process leverages several trading partners and links to a range of back-end services and legacy applications into an end-to-end business process. As Figure 2 shows, the RBC process interacts with different applications such as J2EE, .NET, portals, human workflow, ERP financials, trading partners such as subcontractors, and rules engine interfaces.

    What makes this process interesting is that it requires both the integration of existing applications and new functionality. In our example, a clerk takes an action that causes a PO to be sent out. This is logged against a custom application (which could be J2EE or .NET) that registers the PO and ensures that the total amount does not violate the employee's sign-off authority level. If management approval is required, a workflow is initiated.

    Upon confirmation, the PO needs to kick off a number of business processes, including one that updates the total POs that have been approved by the employee and manager, and one that checks the availability of goods from an existing warehouse or nearby distribution center and requisitions them if they're not available. If the goods aren't available at any location, then the system updates the financials application.

    Notice that in this case, the overall business process is implemented in BPEL. Each of the services can publish a Web service interface that is then orchestrated in BPEL. Using SOAP, WSDL, XML Schema, and BPEL, the business process can be built in a vendor-independent fashion. RBC's business process is shown in Figure 2.

    Using BPEL and other open standards, the task of integrating these systems into an end-to-end business process is straightforward. At any stage, the business process may be changed; for example, by adding extra approval steps, or by updating the BPEL definition of the business process.

    Now consider what's needed when the RBC order process interacts with an outside supplier, STC, which manufactures and distributes t-shirts. RBC and STC are engaged in a collaborative fashion to achieve their common business goal: order fulfillment. For the collaboration to work successfully, RBC must provide the terms under which it's willing to do electronic business with suppliers such as STC.

    RBC has the following simple business rules for collaborating with STC:

    1. RBC places an order for STC t-shirts.
    2. STC acknowledges the purchase order. This initiates a business process in STC that handles the PO. For all RBC knows, STC has an employee at a computer handle the PO, or a sophisticated BPEL process that's linked with back-end manufacturing, logistics, and procurement systems.
    3. After the internal processes within STC regarding the PO are completed - which may take days or even months - STC sends a Purchase Order Completed message back to RBC.
    4. RBC can send a Cancel Order message any time before it receives the Purchase Order Completed message.
    5. If the Cancel Order message arrives at STC before the Purchase Order Completed message is sent, STC aborts its business process and acknowledges this to RBC with the Purchase Order CancelAck message.
    6. If STC has already sent the Purchase Order Completed message, it ignores the Cancel Order message because RBC has agreed that it will honor POs when cancellations are not sent out within an agreed-upon timeframe.
    Based on these business rules of collaboration, the two parties also agree to the following rules of how they exchange messages:
    1. When a PurchaseOrder message is sent from the buyer to the seller and the acknowledgement is received by the buyer, the OrderStatus at both parties is set to New.
    2. When the OrderStatus at both the buyer and seller is New, either a Cancel Purchase Order Message can be sent by the buyer to the seller or a Complete Purchase Order Message can be sent by the seller to the buyer.
    3. When the buyer sends a Cancel Purchase OrderCancel message, the buyer sets itself to CancelPending; when a CancelAck message is sent from the seller to the buyer, this sets both parties to OrderCancelled.
    4. When the seller sends an OrderCompleted message, the OrderStatus at both parties is set to OrderCompleted.
    These terms form the basis of the choreography. The resulting choreography is shown in Figure 3.

    Today, these rules are frequently described in English, and each trading partner's business processes that interact collaboratively can be defined in BPEL or in any other language. What WS-CDL offers is a standardized way to define these interactions, leaving unambiguous documentation of the roles and responsibilities of each. Also, in the future, products that support business process implementation languages such as BPEL could provide tools that would generate, for example, an implementation skeleton for a particular role or validate behavior. Developers looking to define collaborations in B2B situations should keep an eye on WS-CDL. Today, however, BPEL provides the basis for automating business processes on both sides of the firewall.

    The maximum value of SOA architecture is realized by blending SOA with a process-centric view that explicitly defines trading partner collaborations. The basic building blocks to do this are already in place and standards like WS-CDL are emerging to support the full life cycle of collaborative business processes.

    Enterprises looking to automate their business processes around an agile platform can build, service-enable, deploy, secure, and manage services (both internal and external) with BPEL business flows today. Looking further down the road, we expect the ways that business-to-business collaborations can be defined will be greatly enhanced through standards such as Web services choreography and we're actively working in these areas. What's clear today is that there is much value to be gained by streamlining your business around SOA with a process-centric view. Go build!


  • Regarding BPEL engines and the code examples in this article, see:
  • More Stories By Hal Hilderbrad

    Hal Hilderbrad is a Web services architect at Oracle working in the Oracle Application Server core infrastructure group.

    More Stories By Nickolaos Kavantzas

    Nickolaos Kavantzas is a Web services architect at Oracle working in the Oracle Application Server core infrastructure group. He is the architect of the Web Services Choreography Language and the lead editor of the Web Services Choreography Language in the W3C Choreography Working Group. Currently, he is designing Oracle's Web Services Orchestration/Choreography framework.

    More Stories By Ashwini Surpur

    Ashwini Surpur is a principal member, technical staff working on Web Services Choreography at Oracle.

    More Stories By Mohamad Afshar

    Mohamad Afshar, PhD, is VP of Product Management at Oracle. He has product management responsibilities for Oracle's middleware portfolio and is part of the team driving Oracle's investments in SOA on Application Grid - which brings together SOA and data grid technologies to ensure predictable low latency for SOA applications. Prior to joining Oracle, he founded Apama, a complex event processing vendor acquired by Progress Software. He has a PhD in Parallel Systems from Cambridge University, where he built a system for processing massive data sets using a MapReduce framework.

    More Stories By Dave Shaffer

    Dave Shaffer has been helping customers use the Oracle BPEL Process Manager since 2001, managing implementation projects, providing technical training, and ensuring successful implementations. Prior to joining Oracle, Shaffer was a principal consultant at Collaxa, a managing director at Eleven Acceleration, and manager of a professional services group at Apple Computer.

    Comments (0)

    Share your thoughts on this story.

    Add your comment
    You must be signed in to add a comment. Sign-in | Register

    In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

    @MicroservicesExpo Stories
    With containerization using Docker, the orchestration of containers using Kubernetes, the self-service model for provisioning your projects and applications and the workflows we built in OpenShift is the best in class Platform as a Service that enables introducing DevOps into your organization with ease. In his session at DevOps Summit, Veer Muchandi, PaaS evangelist with RedHat, will provide a deep dive overview of OpenShift v3 and demonstrate how it helps with DevOps.
    Any Ops team trying to support a company in today’s cloud-connected world knows that a new way of thinking is required – one just as dramatic than the shift from Ops to DevOps. The diversity of modern operations requires teams to focus their impact on breadth vs. depth. In his session at DevOps Summit, Adam Serediuk, Director of Operations at xMatters, Inc., will discuss the strategic requirements of evolving from Ops to DevOps, and why modern Operations has begun leveraging the “NoOps” approa...
    Docker is hot. However, as Docker container use spreads into more mature production pipelines, there can be issues about control of Docker images to ensure they are production-ready. Is a promotion-based model appropriate to control and track the flow of Docker images from development to production? In his session at DevOps Summit, Fred Simon, Co-founder and Chief Architect of JFrog, will demonstrate how to implement a promotion model for Docker images using a binary repository, and then show h...
    All we need to do is have our teams self-organize, and behold! Emergent design and/or architecture springs up out of the nothingness! If only it were that easy, right? I follow in the footsteps of so many people who have long wondered at the meanings of such simple words, as though they were dogma from on high. Emerge? Self-organizing? Profound, to be sure. But what do we really make of this sentence?
    Containers are changing the security landscape for software development and deployment. As with any security solutions, security approaches that work for developers, operations personnel and security professionals is a requirement. In his session at @DevOpsSummit, Kevin Gilpin, CTO and Co-Founder of Conjur, will discuss various security considerations for container-based infrastructure and related DevOps workflows.
    There once was a time when testers operated on their own, in isolation. They’d huddle as a group around the harsh glow of dozens of CRT monitors, clicking through GUIs and recording results. Anxiously, they’d wait for the developers in the other room to fix the bugs they found, yet they’d frequently leave the office disappointed as issues were filed away as non-critical. These teams would rarely interact, save for those scarce moments when a coder would wander in needing to reproduce a particula...
    Last month, my partners in crime – Carmen DeArdo from Nationwide, Lee Reid, my colleague from IBM and I wrote a 3-part series of blog posts on We titled our posts the Simple Math, Calculus and Art of DevOps. I would venture to say these are must-reads for any organization adopting DevOps. We examined all three ascpects – the Cultural, Automation and Process improvement side of DevOps. One of the key underlying themes of the three posts was the need for Cultural change – things like t...
    It is with great pleasure that I am able to announce that Jesse Proudman, Blue Box CTO, has been appointed to the position of IBM Distinguished Engineer. Jesse is the first employee at Blue Box to receive this honor, and I’m quite confident there will be more to follow given the amazing talent at Blue Box with whom I have had the pleasure to collaborate. I’d like to provide an overview of what it means to become an IBM Distinguished Engineer.
    The cloud has reached mainstream IT. Those 18.7 million data centers out there (server closets to corporate data centers to colocation deployments) are moving to the cloud. In his session at 17th Cloud Expo, Achim Weiss, CEO & co-founder of ProfitBricks, will share how two companies – one in the U.S. and one in Germany – are achieving their goals with cloud infrastructure. More than a case study, he will share the details of how they prioritized their cloud computing infrastructure deployments ...
    Ten years ago, there may have been only a single application that talked directly to the database and spit out HTML; customer service, sales - most of the organizations I work with have been moving toward a design philosophy more like unix, where each application consists of a series of small tools stitched together. In web example above, that likely means a login service combines with webpages that call other services - like enter and update record. That allows the customer service team to writ...
    As we increasingly rely on technology to improve the quality and efficiency of our personal and professional lives, software has become the key business differentiator. Organizations must release software faster, as well as ensure the safety, security, and reliability of their applications. The option to make trade-offs between time and quality no longer exists—software teams must deliver quality and speed. To meet these expectations, businesses have shifted from more traditional approaches of d...
    Between the compelling mockups and specs produced by analysts, and resulting applications built by developers, there exists a gulf where projects fail, costs spiral, and applications disappoint. Methodologies like Agile attempt to address this with intensified communication, with partial success but many limitations. In his session at DevOps Summit, Charles Kendrick, CTO and Chief Architect at Isomorphic Software, will present a revolutionary model enabled by new technologies. Learn how busine...
    If you are new to Python, you might be confused about the different versions that are available. Although Python 3 is the latest generation of the language, many programmers still use Python 2.7, the final update to Python 2, which was released in 2010. There is currently no clear-cut answer to the question of which version of Python you should use; the decision depends on what you want to achieve. While Python 3 is clearly the future of the language, some programmers choose to remain with Py...
    SYS-CON Events announced today that Dyn, the worldwide leader in Internet Performance, will exhibit at SYS-CON's 17th International Cloud Expo®, which will take place on November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Dyn is a cloud-based Internet Performance company. Dyn helps companies monitor, control, and optimize online infrastructure for an exceptional end-user experience. Through a world-class network and unrivaled, objective intelligence into Internet condit...
    Achim Weiss is Chief Executive Officer and co-founder of ProfitBricks. In 1995, he broke off his studies to co-found the web hosting company "Schlund+Partner." The company "Schlund+Partner" later became the 1&1 web hosting product line. From 1995 to 2008, he was the technical director for several important projects: the largest web hosting platform in the world, the second largest DSL platform, a video on-demand delivery network, the largest eMail backend in Europe, and a universal billing syste...
    Somebody call the buzzword police: we have a serious case of microservices-washing in progress. The term “microservices-washing” is derived from “whitewashing,” meaning to hide some inconvenient truth with bluster and nonsense. We saw plenty of cloudwashing a few years ago, as vendors and enterprises alike pretended what they were doing was cloud, even though it wasn’t. Today, the hype around microservices has led to the same kind of obfuscation, as vendors and enterprise technologists alike ar...
    Opinions on how best to package and deliver applications are legion and, like many other aspects of the software world, are subject to recurring trend cycles. On the server-side, the current favorite is container delivery: a “full stack” approach in which your application and everything it needs to run are specified in a container definition. That definition is then “compiled” down to a container image and deployed by retrieving the image and passing it to a container runtime to create a running...
    Containers are revolutionizing the way we deploy and maintain our infrastructures, but monitoring and troubleshooting in a containerized environment can still be painful and impractical. Understanding even basic resource usage is difficult - let alone tracking network connections or malicious activity. In his session at DevOps Summit, Gianluca Borello, Sr. Software Engineer at Sysdig, will cover the current state of the art for container monitoring and visibility, including pros / cons and li...
    Containers have changed the mind of IT in DevOps. They enable developers to work with dev, test, stage and production environments identically. Containers provide the right abstraction for microservices and many cloud platforms have integrated them into deployment pipelines. DevOps and Containers together help companies to achieve their business goals faster and more effectively.
    The web app is agile. The REST API is agile. The testing and planning are agile. But alas, data infrastructures certainly are not. Once an application matures, changing the shape or indexing scheme of data often forces at best a top down planning exercise and at worst includes schema changes that force downtime. The time has come for a new approach that fundamentally advances the agility of distributed data infrastructures. Come learn about a new solution to the problems faced by software organ...