Thursday, November 12, 2015

How to Keep Your Business Process Looking Simple

There are two key words in Business Process Management Notation (and Language) or BPMN for short that very often seemed to be missed. The first is "business" the second "management". In this posting I will discuss the significance of the first, and how you are in control of that.

In BPMN the word business does not wants to express that it is "just" about modeling business processes. The idea is also that these models should be understandable, or even created by the business. Now one can argue that with respect to the latter BPMN does not always seems to deliver on the promise, or at least not for every business. But I know of a few cases where the business analyst creates the non-technical versions of the model (level 1, and 2 as Bruce Silver would call them), and I know of a significant amount of cases where the business or at least the analyst is able to understand BPMN process models. That is to say, if these models have not been cluttered with technical details.

Unfortunately this cluttering happens quicker that you wish, and too often the executable process models are almost beyond comprehension for the business, while there is no good reason for that. And that is too bad, because you then miss the opportunity to let the executable process model being validated by that business. Observing how process modeling is done at some of my projects, unfortunately I have to conclude that quite a few people are not aware of the problem or don't know how to prevent it, and as I did not (yet) found any references that gives a comprehensive overview of the options offered by the Oracle BPM Suite that can help you out, I discuss them in the following.

Embedded Sub-Process

The embedded sub-process is one of the options that most people are aware of, and (generally) reasonably well used. In the example below an embedded sub-process with name "Store Order" contains a script activity "Create Message Header" that constructs the header for the message to be used in the service call activity "Save Order Data". By simply collapsing the embedded sub-process the technical details of how an order is stored, can be hidden for the business that typically does not want to know that a header needs to be created. One could argue they should not even be interested in the fact that this is done synchronously (using a service activity) instead of asynchronously (using a send and receive activity), which also is conveniently hidden by the embedded sub-process.

Except for using it to hide technical details, embedded sub-processes can also be used to determine a scope. This can be done from a business perspective (for example to determine a scope of activities that might be repeated or for which multiple instances should be handled in parallel), but also from a technical perspective (for example as a scope for temporary variables, or exception handling).

The issue I often see with embedded sub-process in action, is that developers very often do not bother collapsing them, still exposing technical details to the business.

One should be aware of a couple of aspects concerning embedded sub-processes. The first is that they are not reusable (meaning you cannot use them elsewhere in the same or any other process model). The second that they come with a little overhead from an audit perspective, as every embedded sub-process results in 2 extra entries (one for the start and one for the end of it).

Reusable Sub-process

A reusable sub-process is created as a separate process. The only thing that distinguishes it from other types of processes, is that it has a none start as well as a none end event, and it cannot have an initiator activity. As the name already suggests, a reusable sub-process is never started directly, but only by calling it from some parent process. This is done by the Call activity.

Going back to the step in the example where we want to save order data, and let's assume the order has to be updated more than once, than this makes it a typical candidate for reuse. In the following example a reusable "Order Storage" reusable sub-process has been created that contains this functionality. It has been made a little bit more complex by including a notification activity that will notify the sales representative every time an update of the order has taken place.

The reusable sub-process has access to the /project/ variables (by value), and its own /process/ variables. In other words, the reusable sub-process has access to the "order" project variable. A choice has been made to pass on the email address of the one that has been notified, as an argument. In the reusable sub-process this email address is stored in a (local) "email" process variable.

The choice to define a variable at project versus process level should be made carefully. Project variables are global variables with the following properties:
  • In case of functionality that is executed in parallel, one should be careful that the parallel threads do not make conflicting changes to the same project variable.
  • Simple type project variables are mapped to protected attributes (also known as mapped attributes or flex field), of which there is a limited number (for example 20 protected text attributes). Their values are stored in separated columns (instead of part of the process payload).
  • The lifespan of a project variable is from its initialization up to the end of the (main) process instance.
Like an embedded sub-process, a reusable sub-process is executed in the same thread. A reusable sub-process is only reusable in the same BPM project (composite) and cannot be shared with other projects. A reusable sub-process adds a little bit more auditing overhead than the embedded sub-process to auditing.

Finally, up to version 12.1.2 a Call activity in a BPM project makes it incompatible with any other revision, meaning that you cannot migrate instances. Period. Not even when you deploy the same revision without changing any bit of your code. For most customers I work with, this is a major limitation, and some therefore choose not to use reusable sub-processes.

Process As a Service

The next alternative to a reusable sub-process is the process-as-a-service, which means that you start it with a message start event or send activity. Any response is returned by a message end event or receive activity. As long as the process-as-a-service is part of the same BPM project (composite) it can make use of the project variables, but only by definition, not by value. So all data has to be mapped to and from the process. You can put the process in the same composite, or put it in a composite of its own. The criteria to do the latter would be reuse over composites. When in a separate composite, you cannot reuse the business objects, nor the project variable definitions.

From a functional perspective, the process-as-a-service is equivalent to a reusable sub-process. From a technical perspective it requires more work if you implement it in a separate composite, and it will add extra overhead to auditing (not only BPM auditing, but also every instance will have its own entry in the COMPOSITE_INSTANCE and CUBE_INSTANCE tables). In 11g you will also have to create some custom mechanism to propagate cancellation of the parent instance to child instances, but in 12c this is automatically done (see also

Detail Activity

Since 12c you can "detail" an activity. With that you can hide logic that is tightly related to an activity, but has to be done using an activity of its own. From the outside a detailed activity looks like any other activity, and keeps the original icon associated with it. The fact that it is detailed you can see by a + sign at the bottom, very much like an embedded sub-process. And basically that is what it is, a specialized embedded activity. You can even have local variables, and in the structure pane it is represented as an embedded sub-process. Again, to keep the business process a "business" process you should try not to get over-exited and put all sorts of logic in it that really belongs somewhere else. Use it only for logic that is tightly coupled to the main activity, but of any importance to the business.

In the following example I have implemented a call to some service that has to happen right after the user activity. It is a technical service call that we don't want to bother the business with, as it concerns a call to a service to confirm the order to the customer. As far as the business is concerned, this is an integral part of the Contact Provider activity, and they should not care if that service is called from the UI or from the process for that matter.

Hope you can make good use of this, and let me know if you have any other suggestion!!

Friday, October 23, 2015

Oracle SOA/BPM: Payload Validation per Composite

In this article I will explain how you can enable payload validation in the Oracle SOA/BPM Suite per composite, both design and deployment time. This works for 11g as well as 12c

When developing BPM processes or SOA services it is advisable enable payload validation on the development server. The reason being that this will force you to work with more representable test data, and in some occasions help you preventing coding errors (like assignment of a string to an integer, or forgetting to map mandatory data in a call). Specifically there where you have to communicate with external systems, this might become very important, not speak of the situation where payload validation is enforced for example by a server bus.

Preferable you have payload validation switched on from the beginning, starting with the development server, but better also for the test server(s). Normally you would leave it off (the default) for production and load and stress test environments (for performance reasons).

However, sometimes you find yourself in a situation where existing composites already violate one or more XML rules. This can make it practically impossible to switch payload validation on for the whole server. You then will have to do it on a composite by composite basis. Fortunately this is supported out-of-the-box by the validateSchema property you can set on a composite, as shown below:

Assuming that you use configuration plans per environment you deploy to, you can switch it on for any environment you want to enable it for, using the following entry in the configuration plan:
When deployed, payload validation will automatically have been enabled for the composite, preventing that you have to do so manually every time you deploy:

No excuses for those lazy developers hiding behind someone else's bad written code!

Wednesday, August 12, 2015

Oracle SOA/BPM 12c: Propagation of Flow Instance Title and Instance Abortion

Recently I wrote this posting regarding an improvement for setting the title of a flow instance in Oracle BPEL, and BPMN 12c. In this posting I will discuss two related improvements that comes with SOA/BPM Suite 12c, being that the flow instance abortion is automatically propagated from one instance to the other, as well as the flow instance title. Or more precisely, for every child instance the initiating instance is shown together with its name.

Since 12c the notion of composite instance is superseded by that of flow instance, which refers to the complete chain of calls starting from one main instance to any other composite, and further. Every flow has a unique flowId which is automatically propagated from one instance to the other.

Propagation of Flow Instance Title

This propagation does not only apply to the flowId, but also to the flowInstanceTitle, meaning that if you set the flowInstanceTitle for the main instance all called composites automatically get the same title.

So if the flowInstanceTitle is set on the main instance:

Then you will automatically see it for every child instance as well:

Trust but verify is my motto, so I tried it for a couple of combinations of composite types calling each other, including:
  • BPM calling BPEL calling another BPEL
  • BPM initiating a another composite with a Mediator and BPEL via an Event
  • Mediator calling BPEL

Flow Instance Abortion

When you abort the instance of the parent, then all child instances are aborted as well.

In the following flow trace you see a main BPM process that kicks of:
  1. A (fire&forget) BPEL process
  2. Throws an Event that is picked up by a Mediator
  3. Calls another BPM process
  4. Schedules a human task

On its turn the BPEL process in step 1 kicks of another BPEL process (request/response). Finally the BPM process in step 3 also has a human task:

Once the instance of the main process is aborted, all child instances are automatically aborted as well, including all Human Tasks and composites that are started indirectly.

The flip-side of the coin is that you will not be able to abort any individual child instance. When you go to a child composite, select a particular child instance and abort, the whole flow will be aborted. That is different from how it worked with 11g, and I can imagine this will not always meet the requirements you have.

Another thing that I find strange is that the Mediator that is started by means of an event, even is aborted when the consistency level is set to 'guaranteed' (which means that event delivery happens in a local instead of a global transaction). Even though an instance is aborted, you may have a requirement to process that event.

But all in all, a lot easier to get rid of a chain of processes instances than with 11g!!

Thursday, July 16, 2015

How to Hide Actions in OBPM 12c Workspace

In this article I explain how to hide the actions in the drop-down in Workspace.

In some situations you may need to hide the actions that are shown in the Actions drop-down in Workspace.

One way to do so is by configuring the access that users with a specific Workspace role have for a specific task (not to be confused with a swim-lane role), by going to the task definition -> Access -> Actions. For example, if you want to disable that an assignee can acquire or reassign a task, you can uncheck the "Acquire" and "Reassign" check boxes in the "Assignees" column.

You can also uncheck the outcomes, for example like the "APPROVE" and "REJECT" actions in the picture above. However, this will make that the assignee cannot choose the outcomes at all, because then the buttons are not rendered either. When you uncheck all outcomes this will practically make that the assignee cannot execute the activity at all, which is probably not what you want. As a matter of fact, you will also not be able to commit the task using the updateTaskOutcome() operation on the TaskService, as you will get an error when tying to do so.

A more practical case for hiding the outcomes from the drop-down menu is where the user should not be able to chose them from there, but should be able to chose the actions using buttons on the screen. An example would be where you need to submit data through the form, because it has to update data in the database directly (instead of via a service call in the process). This you can do through the Configure option in the task definition.

When you check "Require payload review before approval" the user will not be able to chose any action from the drop down. However, the buttons will be available on the screen.

Wednesday, July 15, 2015

Starting a Process using a Timer with a Duration in Oracle BPM

In this blog article I explain three options to configure a timer start event based upon some configurable duration.

As far as I know firing a timer based on a duration is only applicable in case of a Timer Event Sub-process. Let me know if you think otherwise.

In case of an Event Sub-process the timer starts at the same moment when the process instance starts. There is no way to change it at any point after that. Given this , you can use one of the following three options that I discuss below. If you know of some oher way, again: let me know!

Input Argument

You can use an element that is part of the request of the process. In the following example there is one input argument called 'expiry' of type duration which is mapped to a process variable:

The process variable can then used to start the timer using an straightforward simple XPath assignment:

Preference in composite.xml

You can also configure a preference in the composite.xml file. Such a preference belongs to a specific component, and starts with "preference" (or "bpel.preference", but you can leave "bpel." out). Using the dot as a delimiter you can post-fix that with the preference name to use:

You can then set the timer using the ora:getPreference() XPath function. All these preferences are strings, but if the value is an ISO duration it will automatically be converted to a duration.

Domain Value Map

A third option is to configure the duration using a Domain Value Map or DVM for short. In the following example a DVM file is used for configuration parameters as a name-value pair:


The timer can be instantiated using the dvm:lookupValue() XPath function, as show in the following picture:

What to Choose?

This depends on the requirements.

If your consumer should be able to determine the duration, you should pass it on as a request parameter.

If the business wants to change it run-time than using the DVM is the best option. The initial value is determined design-time but can be changed run-time via SOA Composer (the same tool via which business rules can be changed).

Otherwise the composite preference is your weapon of choice. Also for this preference the initial value is determined design-time, but can still be changed after deployment by IT using the MBean Browser in Enterprise Manager.

Thursday, July 09, 2015

Using a Parallel Gateway without a Merge in OBPM

In this blog article I give a brief explanation regarding some aspect of the behavior of the parallel gateway in Oracle BPM. It has been changed on September 15 2015 by adding the remark at the end regarding a Complex Merge (thanks to Martien van den Akker).

For the BPMN modelers among us, I have a small quiz.

Given a process model like this, what would be the behavior of Oracle BPM?

  1. It does not compile because OBPM thinks it is not valid BPMN
  2. The flows with Activity 1 and 2 are merged, the token moves to the End event of the process, and then the instance finishes.
  3. Activity 1 and 2 are executed, and then OBPM waits in the merge because to continue all tokens have to reach the merge.
  4. The flows with Activity 1 and 2 are merged, the token moves to the End event of the process, and in the meantime waits until the timer expires. It will not end before the token reached the Terminate end event, because not all flows from the split are explicitly merged the whole process itself serves as an implicit merge.

If this would be some magazine, I would now tell you to go to the last page and turn it upside down to read the answer. Or wait until the next issue in which I announce the prize winners.

Alas, no such thing here so let me give you the answer straight away, which is answer 4:

I must admit I was a bit surprised, as I seem to remember that some bundle patches or patch sets ago it would have been a. But when you look at the BPMN specification there is nothing that says that a parallel gateway always has to have a merge. Strange then that OBPM does not let you draw a model without one, but at least it works with a merge with just one ingoing flow.

As a matter of fact, to make the End even actually end the instance, you should change it into an Intermediate Message Throw event, and end the process with a Terminate End event as well. Run-time that looks awkward, because even when your process ends successfully it has the state Terminated.

Fir this reason and and perhaps because your audience might just not understand this model, specifically when it concerns a larger one, the following alternative perhaps is easier to understand. You now can choose if and which flow you want to end with a Terminate End event.

To force that the process continues after the merge, a Complex Merge is used that aborts all other pending parallel flows when the timer expires.

Wednesday, June 24, 2015

Groovy Time! How to use XML dateTime and duration in BPM 12c

In this article I show some examples of handling XML dateTime and durations in Groovy in the context of a Oracle BPM 12c application.

Working with dates and durations in Java has always been painful. Mainly because date and time is a complex thing, with different formats and time zones and all, but I sometimes wonder if it has not been made overly complex. Anyway. Working with XML dates is even more complex because the limited support by XPath functions. Too bad because in BPM applications that work with dates this has to be done very often, and as a result I very often see the need to create all kinds of custom XPath functions to mitigate that.

This issue of complexity is no different for Groovy scripting in Oracle BPM 12c. And let handling of dates be a typical use case for using Groovy scripting because of this limited support by XPath. Therefore, to get you started (and help myself some next time) I would like to share a couple of Groovy code snippets for working with XML dates and durations that may be useful. These example are based on working with the XML dateTime type, and do not handle with the complexity of time zones and different formats. In my practice this is 99% of the use cases that I see.

In my opinion you still should limit using Groovy to handle dates and to the minimum, and rather use custom XPath functions, or create a Java library which you can can import in Groovy. But when you have to, this just might come in handy.

Instantiate an XML Date

If you have an XML element of type dateTime, you use an XmlCalender object. An XmlCalender object with the current time can instantiated as shown below:

Date now = new Date()
GregorianCalendar gregorianNow = new GregorianCalendar()
XmlCalendar xmlDate = XmlCalendarFactory.create(gregorianNow)

Instantiate a Duration and Add it to the Date

To instantiate a duration you use an XmlDuration object. In the code below a duration of one day is added to the date:

XmlDuration xmlDuration = new XmlDuration("P1D")

The string to provide is of type ISO duration.

The imports to use can also be a pain to find. That actually took me the most time of all, but that can just be me. The ones needed for the above are shown in the following picture (you can get to it by using clicking on Select Imports on the top-right corner of the Groovy script.