Welcome!

Industrial IoT Authors: Craig Lowell, Carmen Gonzalez, Elizabeth White, Pat Romanski, William Schmarzo

Related Topics: Microservices Expo, Industrial IoT

Microservices Expo: Article

BPEL Processes and Human Workflow

Using BPEL in business processes that require human interaction

Business Process Execution Language (BPEL), one of the key technologies for Service Oriented Architecture (SOA), has become the accepted mechanism for defining and executing business processes in a common vendor-neutral way. Companies ranging from Oracle, IBM, Microsoft, SAP, and BEA to smaller organizations such as Fuego and Lombardi have committed to BPEL as a building block for SOA. BPEL, which has been designed specifically for defining business processes, supports typical interactions such as synchronous and asynchronous operation invocation, sequential and parallel flows, message correlations, fault and compensation handlers and activities triggered by events. Business processes often require human interactions as well.

Since the BPEL specification doesn't address them, you might think BPEL isn't suitable for business processes that involve people. But that's not the case. In this article, we'll look at different choices for human workflow support - including future possible extensions to the BPEL specification and current vendor solutions - and analyze their relevance in practical scenarios. We'll also discuss real-world scenarios in which BPEL and human workflow services are used and show how one company is using BPEL to integrate people with processes - and the benefits achieved through this approach.

User Interaction in Business Processes
BPEL business processes are defined as collections of activities that invoke services. BPEL doesn't make a distinction between services provided by applications and other interactions, such as human interactions. And that's important since real-world business processes often integrate not only systems and services but also users. User interactions in business processes can be simple, such as approving certain tasks or decisions, or complex, such as delegation, renewal, escalation, nomination, or chained execution.

Task approval is the simplest and probably the most common user interaction. In a business process for opening a new account, a user interaction might be required to decide whether the user is allowed to open the account. If the situation is more complex, a business process might require several users to make approvals, either in sequence or in parallel. In sequential scenarios, the next user often wants to see the decision made by the previous user. Sometimes, particularly in parallel user interactions, users aren't allowed to see the other users' decisions. This improves the decision potential. Sometimes one user doesn't even know which other users are involved - or whether any other users are involved at all.

A common scenario for involving more than one user is workflow with escalation. Escalation is typically used in situations where an activity doesn't fulfill a time constraint. In such a case, a notification is sent to one or more users. Escalations can be chained, going first to the first-line employees and advancing to senior staff if the activity isn't fulfilled.

Sometimes it's difficult or impossible to define in advance which user should perform an interaction. In this case, a supervisor might manually nominate the task to other employees; the nomination can also be made by a group of users or by a decision-support system.

In other scenarios, a business process may require a single user to perform several steps that can be defined in advance or during the execution of the process instance. Even more complex processes might require that one workflow is continued with another workflow.

User interactions aren't limited to approvals; they can also include data entries or process management issues, such as process initiation, suspension, and exception management. This is particularly true in long-running business processes, where, for example, user exception handling can prevent costly process termination and related compensation for those activities that have already been successfully completed.

As a best practice for human workflows, it's usually not wise to associate human interactions directly with specific users; it's better to connect tasks to roles and then associate those roles with individual users. This gives business processes greater flexibility, letting any user with a certain role interact with the process and enabling changes to users and roles to be made dynamically.

BPEL and User Interaction
So far we've seen that user interaction in business processes can get quite complex. Although BPEL specification 1.1 (and the upcoming BPEL 2.0) doesn't specifically cover user interactions, BPEL is appropriate for human workflows. Several vendors today have created workflow services that leverage the rich BPEL support for asynchronous services. In this fashion, people and manual tasks become just another asynchronous service from the perspective of the orchestrating process and the BPEL processes stay 100% standard.

We now see the next generation of workflow specifications emerging around BPEL with the objective of standardizing the explicit inclusion of human tasks in BPEL processes. This proposal is called BPEL4People and was originally put forth by IBM and SAP in July 2005. Other companies, such as Oracle, have also indicated that they intend to participate in and support this effort.

The most important extensions introduced in BPEL4People are people activities and people links. People activity is a new BPEL activity used to define user interactions; in other words, tasks that a user has to perform. For each people activity, the BPEL server must create work items and distribute them to users eligible to execute them. People activities can have input and output variables and can specify deadlines.

To specify the implementation of people activities, BPEL4People introduced tasks. Tasks specify actions that users must perform. Tasks can have descriptions, priorities, deadlines, and other properties. To represent tasks to users, we need a client application that provides a user interface and interacts with tasks: it can query available tasks, claim and revoke them, and complete or fail them.

To associate people activities and the related tasks with users or groups of users, BPEL4People introduced people links. People links are somewhat similar to partner links; they associate users with one or more people activities. People links are usually associated with generic human roles, such as process initiator, process stakeholders, owners, and administrators.

The actual users who are associated with people activities can be determined at design time, deployment time, or runtime. BPEL4People anticipates the use of directories such as LDAP to select users; however, it doesn't define the query language used to select users. Rather, it foresees the use of LDAP filters, SQL, XQuery, or other methods.

BPEL4People proposes complex extensions to the BPEL specification, however so far it's still quite high level and doesn't yet specify the exact syntax of the new activities mentioned above. Until the specification becomes more concrete, we don't expect vendors to implement the proposed extensions. But while BPEL4People is early in the standardization process, it shows a great deal of promise.

Finally, as it stands today, the BPEL4People proposal raises an important question: Is it necessary to introduce such complex extensions to BPEL to cover user interactions? As described previously, some vendor solutions model user interactions as just another Web Service with well-defined interfaces for both BPEL processes and client applications. This approach doesn't require any changes to BPEL; to become portable, it would only need an industry-wide agreement on the two interfaces. And of course, both interfaces can be specified with WSDL, which gives developers great flexibility and lets them use practically any environment, language, or platform that supports Web Services. An example of such an approach is the Workflow Service in the Oracle BPEL Process Manager, which we'll describe later.

First, we should complete the discussion of standards efforts by pointing out that there are several older workflow specifications, most notably Wf-XML from the Workflow Management Coalition (WfMC). Wf-XML is an XML-based proposal for consistent data transfer between workflow engines. As far as we know, it hasn't been used in any major BPEL engine, probably because WfMC and the Business Process Management Initiative jointly released the XML Process Definition Language. XPDL focuses on the design-time interoperability of different workflow products and is therefore only of very limited relevance to the BPEL community.

Clearly, a single standard approach hasn't yet been adopted for extending BPEL to include human tasks and workflow services. However, this doesn't mean that developers can't use BPEL to develop business processes with user interactions. In the rest of this article, we're pragmatic and describe one approach that works today for integrating user interactions in standard BPEL processes.

Workflow Integration with BPEL
To interleave user interactions with service invocations in BPEL processes we can use a workflow service, which interacts with BPEL using standard WSDL interfaces. This way, the BPEL process can assign user tasks and wait for responses by invoking the workflow service using the same syntax as for any other service. The BPEL process can also perform more complex operations such as updating, completing, renewing, routing, and escalating tasks.

After the BPEL process has assigned tasks to users, users can act on the tasks by using the appropriate applications. The applications communicate with the workflow service by using WSDL interfaces or another API (such as Java) to acquire the list of tasks for selected users, render appropriate user interfaces, and return results to the workflow service, which forwards them to the BPEL process. User applications can also do other tasks such as reassign, escalate, route, suspend, resume, and withdraw. Finally, a workflow service may allow other communication channels, such as e-mail and SMS, as shown in Figure 1.

Oracle BPEL Process Manager uses such an architectural abstraction to integrate standard BPEL functionality with workflow. Loose coupling lets workflow services be deployed on any supported application server. It also allows evolving the workflow service, as specifications such as BPEL4People emerge, without having to change the existing BPEL processes. The workflow service includes a simple yet powerful set of Java APIs and WSDL interfaces for building UI workflow interfaces; these offer maximum interoperability for UI approaches, including JSF, AJAX, .NET, and Adobe Flex.

Case Study
Let's look at a case study that shows how you can incorporate human interactions with BPEL. Consider a business process for opening a new bank account; we'll call this process "New Account." The customer provides the necessary details (such as name, address, social security number, and initial deposit) to open the account. Once the process is initiated, the customer may want to track the status of the request and respond to any additional queries from the bank. This process requires a workflow to enable customer participation and process monitoring so that the customer can track the request status.


More Stories By Matjaz Juric

Dr Matjaz B. Juric is a professor at the University of Maribor. He is the author of Business Process Execution Language for Web Services, 2nd Edition, published by Packt Publishing (www.packtpub.com), and several other books, articles, and conference presentations. He is also the author of courses offered by BPELmentor.com - a training, mentoring, and consulting company (www.BPELmentor.com).

More Stories By Doug H. Todd

Doug Todd is CTO of Enterra Solutions in Yardley, Pa. He has more than 20 years of experience in systems architecture, applications architecture, systems integration, and applications integration with major corporations. Todd is responsible for Enterra’s overall IT strategy and tactical implementation, enterprise information architecture, and technology product offerings.

Comments (4) View Comments

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.


Most Recent Comments
Arnaud Blandin 05/12/06 12:42:10 PM EDT

Hi,

Thanks for this great article that summarizes part of the issue of integrating Human Workflow in BPEL processes.
At Intalio, we have decided to implement BPEL4People without extending the BPEL 2.0 spec. Our implementation is based on a 5 year experience of integrating human users within business processes.
The Intalio|Workflow component is based on XForms and a set of processes deployed as BPEL 2.0 code on the Intalio|Server (aka PXE). The nice thing is that the forms representing the tasks are edited graphically through a WYSISWYG editor integrated in Intalio|Designer, an eclipse based application.
It leads me to another comment, having BPEL supporting human interaction is one side of the problem. The other side is focused on the business side of the process design. It is important to have a visual representation of Human interactions within a process. Intalio|Designer has adopted the BPMN specification to describe business processes but BPMN does not yet fully support 'Human task' as a first class citizen.

One last comment is that Intalio|Workflow Community Edition comes for free as well as the entire product ;). Check out our community website to become a member of our community.

SYS-CON Belgium News Desk 04/12/06 03:16:51 PM EDT

Business Process Execution Language (BPEL), one of the key technologies for Service Oriented Architecture (SOA), has become the accepted mechanism for defining and executing business processes in a common vendor-neutral way. Companies ranging from Oracle, IBM, Microsoft, SAP, and BEA to smaller organizations such as Fuego and Lombardi have committed to BPEL as a building block for SOA. BPEL, which has been designed specifically for defining business processes, supports typical interactions such as synchronous and asynchronous operation invocation, sequential and parallel flows, message correlations, fault and compensation handlers and activities triggered by events. Business processes often require human interactions as well.

SYS-CON India News Desk 04/12/06 02:31:28 PM EDT

Business Process Execution Language (BPEL), one of the key technologies for Service Oriented Architecture (SOA), has become the accepted mechanism for defining and executing business processes in a common vendor-neutral way. Companies ranging from Oracle, IBM, Microsoft, SAP, and BEA to smaller organizations such as Fuego and Lombardi have committed to BPEL as a building block for SOA. BPEL, which has been designed specifically for defining business processes, supports typical interactions such as synchronous and asynchronous operation invocation, sequential and parallel flows, message correlations, fault and compensation handlers and activities triggered by events. Business processes often require human interactions as well.

SOA Web Services Journal News Desk 04/12/06 02:20:52 PM EDT

Business Process Execution Language (BPEL), one of the key technologies for Service Oriented Architecture (SOA), has become the accepted mechanism for defining and executing business processes in a common vendor-neutral way. Companies ranging from Oracle, IBM, Microsoft, SAP, and BEA to smaller organizations such as Fuego and Lombardi have committed to BPEL as a building block for SOA. BPEL, which has been designed specifically for defining business processes, supports typical interactions such as synchronous and asynchronous operation invocation, sequential and parallel flows, message correlations, fault and compensation handlers and activities triggered by events. Business processes often require human interactions as well.

@ThingsExpo Stories
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
In this strange new world where more and more power is drawn from business technology, companies are effectively straddling two paths on the road to innovation and transformation into digital enterprises. The first path is the heritage trail – with “legacy” technology forming the background. Here, extant technologies are transformed by core IT teams to provide more API-driven approaches. Legacy systems can restrict companies that are transitioning into digital enterprises. To truly become a lead...
The Internet of Things (IoT) promises to simplify and streamline our lives by automating routine tasks that distract us from our goals. This promise is based on the ubiquitous deployment of smart, connected devices that link everything from industrial control systems to automobiles to refrigerators. Unfortunately, comparatively few of the devices currently deployed have been developed with an eye toward security, and as the DDoS attacks of late October 2016 have demonstrated, this oversight can ...
You have great SaaS business app ideas. You want to turn your idea quickly into a functional and engaging proof of concept. You need to be able to modify it to meet customers' needs, and you need to deliver a complete and secure SaaS application. How could you achieve all the above and yet avoid unforeseen IT requirements that add unnecessary cost and complexity? You also want your app to be responsive in any device at any time. In his session at 19th Cloud Expo, Mark Allen, General Manager of...
Bert Loomis was a visionary. This general session will highlight how Bert Loomis and people like him inspire us to build great things with small inventions. In their general session at 19th Cloud Expo, Harold Hannon, Architect at IBM Bluemix, and Michael O'Neill, Strategic Business Development at Nvidia, discussed the accelerating pace of AI development and how IBM Cloud and NVIDIA are partnering to bring AI capabilities to "every day," on-demand. They also reviewed two "free infrastructure" pr...
As data explodes in quantity, importance and from new sources, the need for managing and protecting data residing across physical, virtual, and cloud environments grow with it. Managing data includes protecting it, indexing and classifying it for true, long-term management, compliance and E-Discovery. Commvault can ensure this with a single pane of glass solution – whether in a private cloud, a Service Provider delivered public cloud or a hybrid cloud environment – across the heterogeneous enter...
"Dice has been around for the last 20 years. We have been helping tech professionals find new jobs and career opportunities," explained Manish Dixit, VP of Product and Engineering at Dice, in this SYS-CON.tv interview at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Extracting business value from Internet of Things (IoT) data doesn’t happen overnight. There are several requirements that must be satisfied, including IoT device enablement, data analysis, real-time detection of complex events and automated orchestration of actions. Unfortunately, too many companies fall short in achieving their business goals by implementing incomplete solutions or not focusing on tangible use cases. In his general session at @ThingsExpo, Dave McCarthy, Director of Products...
"ReadyTalk is an audio and web video conferencing provider. We've really come to embrace WebRTC as the platform for our future of technology," explained Dan Cunningham, CTO of ReadyTalk, in this SYS-CON.tv interview at WebRTC Summit at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
The many IoT deployments around the world are busy integrating smart devices and sensors into their enterprise IT infrastructures. Yet all of this technology – and there are an amazing number of choices – is of no use without the software to gather, communicate, and analyze the new data flows. Without software, there is no IT. In this power panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, Dave McCarthy, Director of Products at Bsquare Corporation; Alan Williamson, Principal...
Businesses and business units of all sizes can benefit from cloud computing, but many don't want the cost, performance and security concerns of public cloud nor the complexity of building their own private clouds. Today, some cloud vendors are using artificial intelligence (AI) to simplify cloud deployment and management. In his session at 20th Cloud Expo, Ajay Gulati, Co-founder and CEO of ZeroStack, will discuss how AI can simplify cloud operations. He will cover the following topics: why clou...
Video experiences should be unique and exciting! But that doesn’t mean you need to patch all the pieces yourself. Users demand rich and engaging experiences and new ways to connect with you. But creating robust video applications at scale can be complicated, time-consuming and expensive. In his session at @ThingsExpo, Zohar Babin, Vice President of Platform, Ecosystem and Community at Kaltura, discussed how VPaaS enables you to move fast, creating scalable video experiences that reach your aud...
WebRTC is the future of browser-to-browser communications, and continues to make inroads into the traditional, difficult, plug-in web communications world. The 6th WebRTC Summit continues our tradition of delivering the latest and greatest presentations within the world of WebRTC. Topics include voice calling, video chat, P2P file sharing, and use cases that have already leveraged the power and convenience of WebRTC.
"At ROHA we develop an app called Catcha. It was developed after we spent a year meeting with, talking to, interacting with senior citizens watching them use their smartphones and talking to them about how they use their smartphones so we could get to know their smartphone behavior," explained Dave Woods, Chief Innovation Officer at ROHA, in this SYS-CON.tv interview at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life sett...
DevOps is being widely accepted (if not fully adopted) as essential in enterprise IT. But as Enterprise DevOps gains maturity, expands scope, and increases velocity, the need for data-driven decisions across teams becomes more acute. DevOps teams in any modern business must wrangle the ‘digital exhaust’ from the delivery toolchain, "pervasive" and "cognitive" computing, APIs and services, mobile devices and applications, the Internet of Things, and now even blockchain. In this power panel at @...
The Internet of Things will challenge the status quo of how IT and development organizations operate. Or will it? Certainly the fog layer of IoT requires special insights about data ontology, security and transactional integrity. But the developmental challenges are the same: People, Process and Platform and how we integrate our thinking to solve complicated problems. In his session at 19th Cloud Expo, Craig Sproule, CEO of Metavine, demonstrated how to move beyond today's coding paradigm and sh...
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.