Flows — Concepts and terms

On the Diagram tab of a flow, you can interact with three alternative presentations of the flow diagram:

• Discovery Map — A high-level abstract presentation useful for business analysts
• Process Modeler diagram — A detailed, step-by-step presentation, edited directly in a browser window.
• Visio diagram — A detailed, step-by-step presentation, edited using Microsoft Visio.

Process Modeler

New in V6.2, Process Modeler allows more direct manipulation of shapes, connectors, and layouts directly in a browser window. Process Modeler is recommended for new flows developed in V6.2+. All runtime capabilities of Visio-based flows are also available in Process Modeler -based flows.

Visio editing

Application developers use Microsoft Visio to create, edit, and evolve a flow. PRPC uploads the resulting VSD file, including the Shape Parameters details from the workstation. Both the diagram image (a JPG file) and the rule details are saved with the flow.

To start Visio on your workstation, click the Flow Edit toolbar button (). Create and evolve the flow in Visio as needed using familiar Windows techniques such as drag-and-drop. As you work, you can enter the names of utility shapes, decision shapes, assignment shapes, router shapes, flow actions and the rules that these shapes reference. If some of the activities and other rules for these shapes do not yet exist, you can leave the rule in draft mode.

As you exit from Visio, the system uploads the flow diagram (and the extensive data structure that Visio contains), and saves it in the flow.

You can't test a flow that has Availability set to No/Draft. You can test the flow if the Availability is set to Yes, even if the Visio DRAFT mode () is in force, indicating that not all the activities, properties, or other rules are yet defined.

At runtime, a user can start the execution of a flow by entering a new work item. The system examines the property pyFlowName, in the data transform instance for the class, to determine which flow to start. The flow operates on the work item to advance it through the business process that the flow implements, performing automated steps automatically, or creating assignments for users as appropriate.

You can think of a work item as located "on" one shape or arrow of the flow at any one instant, until the work item becomes resolved or the flow ends. Alternatively, you can think of the flow operating on the data (properties) in the work item until the flow finishes or the work item becomes resolved. Both points of view are correct.

A flow may define many optional detours, side trips, and branches reflecting decisions reached along the way. The path that one work item follows through the flow depends on its own requirements, automatic decisions in rules (such as decision trees and map values) and on available resources. For example:

• One mortgage application that fails to meet the automatic credit approval rules may require special research, while others are handled automatically
• An arriving customer service call in Mary’s territory may be routed to Tom if Mary is unavailable
• A request that is in a foreign language may be routed to a manager who can decide who among his or her team is best qualified to handle the request. Normal requests, not in a foreign language, may be routed automatically based on a round-robin algorithm.
• The system can randomly select one work item out of every hundred for a quality review.

As a flow executes, the following processing often occurs:

• The system generates a unique work item ID for a new work item. (This occurs for starter flows, those for which the Creates a new work item? box on the Flow form is selected.)
• As needed, it creates assignments for human users reflecting the need for more facts, judgments, and places the assignment into an appropriate user worklist or workbasket. After a user (or in some cases an agent or external participant) perform an assignment, the work item progresses farther through the flow.
• The system automatically makes decisions, urgency calculations, and gathers data automatically from many sources including outside systems.
• Rules promote compliance with service level goals, and alerts management or raises the urgency value when processing does not meet these goals. This is known as escalation.
• Processing of the flow ends when an End shape is reached. The work item may or may not be resolved at that point.

The Process Explorer tool presents — for the currently selected application — starter flows and the subprocesses they call in a graphical form. See Process and Rules category — Processes page.

• A flow that contains no assignments, and so can execute from start to end without human input, is known as a straight-through process.
• A flow that consists only of assignments or decisions and meets other criteria is known as a screen flow.
• A flow that creates a new work item is called a starter flow.
• A flow that is called by another flow is known as a subprocess; the calling flow is called parent flow. Processing of a subprocess is synchronous, meaning that the calling flow execution pauses for the duration of the subprocess. When the subprocess execution reaches an End shape, the calling flow can continue (if additional shapes are present). See Flows — Editing in Visio — Call or Branch to a Subprocess and Flow form — Editing with Process Modeler — Editing the Subprocess shape properties.

In some business processes, the order of certain steps is not important as long as all the steps get done. In other situations, a step can be considered complete when either of two other steps finishes.

The Split Join facility ( or ) supports such asynchronous operation, by allowing processing of two or more subprocesses to proceed in parallel. For example, a contract may need approval of both a legal reviewer and a purchasing department reviewer, but order is not important. In the 1980's era of paper forms and in-boxes, only one of these two has the paper — artificial sequencing. With a work-object and a flow that uses Split Join, each subprocess can create an assignment, and the two reviewers can proceed independently.

See Flow form — Editing in Process Modeler — Split Join shape properties and Flows — Editing in Visio — Split Join shape.

Split Join parallel processing occurs only when considered at the business process level. Although two assignments exist, they both belong to a single work item. During the minutes or seconds that either user performs the assignment (thus updating the work item), the system locks the work item and so the work item is not available to the other user.

Similarly, at a more atomic level, if the two users both access a single-node PRPC system that has a single JVM and single CPU chip, no parallel processing occurs at the Java thread level, even when the two users work on different work items.

The Split For Each facility ( or ) causes multiple subprocesses to start, one for each page of a Page List property. Processing can resume after any one, or all, of the subprocesses end.

See Flows — Editing in Visio — Split for Each shape and Flow form — Process Modeler — Editing the Split For Each shape.

A Spinoff shape starts asynchronous execution of a different flow, on the same work item or a different work item. Processing of the current flow does not pause or wait for results from the other flow.

To create a spinoff when editing with Process Modeler, use a Subprocess shape ( ). Select the Spinoff Flow checkbox. See Flow form — Editing with Process Modeler — Editing the Subprocess shape properties.

To create a spinoff when editing with Visio, add the Spinoff shape (). See Flows — Editing in Visio — Spinoff shape.

PRPC offers ways for a flow execution to be started for an existing (open) work item. These are alternatives to calling a subprocess, using a Split Join shape, or using a Split for Each shape:

• Users can access an open work item in update mode, click the  Start a new process   button, and choose a second flow to start. This button is available on most Update user forms. Users may be prompted to enter flow parameters to complete the operation. The  Start a new process   button lists all the eligible flows with the Can be added to a work item? box selected on the Flow form. (To include this button on a user form, reference the standard section Work-.Flows in a harness.)
• Users can select the standard flow action Work-.AddFlow, Work-.AddCovered, or Work-.AddtoCover to start a new flow execution.

Several system-maintained properties in a work item record the current state of flow executions in process. For example, the integer property @baseclass.pxFlowCount indicates how many flow executions are in process for the work item.

The Page Group property @baseclass.pxFlow contains a page of facts about each execution:

• pyFlowType — Second key part of the flow
• pxAssignmentKey — Key of the current assignment instance for this flow execution. typically an instances of the Assign-Workbasket or Assign-Worklist class.
• pyLastFlowStep — Internal name of the most recent shape or connector processed
• pyNextFlowStep — Internal name of the next shape or connector to be processed
• pyFlowParameters — A classless page containing parameters used to start this flow