Business Process Library Q Business Process Management

Conditional Sequence Flow

From Q-BPM
Jump to: navigation, search
Conditional Sequence Flow
Conditional Sequence Flow

Conditional Sequence Flow is a type of Sequence Flow, and a conditional expression is defined at its origin.

Contents

Overview

What is XOR-Split / OR-Split?
  • XOR-Split

A split at which only one flow that satisfies a specified condition is selected and decided among multiple branching flows

  • OR-Split

A split at which multiple flows that satisfy specified conditions are selected and decided among multiple branching flows

Conditional Sequence Flow is a Sequence Flow that has a conditional expression near its origin. A conditional expression is used when either of the following decision branching is done.

Conditional Sequence Flow has a diamond-shaped marker at its origin (the root of an arrow symbol in terms of representation). This diamond-shaped marker is called "conditional marker." When the origin of Conditional Sequence Flow is attached to Gateway, the Gateway itself works as a conditional marker. So in this case we do not use the diamond-shaped marker. "Conditional markers" are used only in case of Conditional Sequence Flows departing from Activities.

Sequence Flow that is not connected to a diamond-shaped marker is specially called Unconditional Sequence Flow.

Usage

Flow object

Image:Objectoo.png

Two types of flow objects shown below can be used as an origin of Conditional Sequence Flow.

  • Activity
  • Decision Gateway (A gateway that works as XOR-Split or OR-Split)

While BPMN has flexibility to deal with various business processes, it can have multiple representations for the same process. (This feature is generally called "redundancy" of BPMN.) For example, there are primarily two possible ways to represent the mechanism of Conditional Sequence Flow on OR-Split.

A process diagram regarding a connection to Activity and a process diagram regarding a connection to Decision Gateway are representing the same process even though the representations are different. In the two diagrams shown below, Sequence Flows of an orange color are Conditional Sequence Flows.

Connection to Activity

Conditional Sequence Flow is mainly used in case of a flow that works as OR-Split. In such a case, the "conditional marker" needs to be attached to the origin of the Sequence Flow. When more than two flows are originating from one flow object, we need to use Default Sequence Flow.

Figure 1: Connection to Activity
Figure 1: Connection to Activity

Connection to Decision Gateway

In spite of the absence of "conditional markers," all Sequence Flows departing from "XOR Gateways" or "OR Gateways", which are called "Decision Gateways" as a whole, are Conditional Sequence Flows. They are used in flows that are XOR-Splits or OR-Splits. Because no "decision" is made in case of AND-Splits, Sequence Flows departing from AND Gateways are not Conditional Sequence Flows, but Unconditional Sequence Flows.

Figure 2: Connection to OR Gateway
Figure 2: Connection to OR Gateway

Condition Decision Mechanism

At OR-Split or XOR-Split, each of multiple Conditional Sequence Flows is assigned one conditional expression. However, when there are more than two conditional expressions, "the order and the way in which the conditional expressions are evaluated" depend on whether it is OR-Split or XOR-Split.

  • In case of OR-Split (Refer to Figure 2.)
    All conditional expressions are evaluated in order from the expression written on the top. Then, the Token will flow into all flows corresponding to the conditional expression that are evaluated to be "true." Therefore, at OR-Split, the Token could flow into multiple flows. In Figure 2, if both of conditional expression A and B are evaluated to be "true," both "Activity 1" and "Activity 2" will be executed.
  • In case of XOR-Split
    Conditional expressions are evaluated in order from the expression written on the top. If there is a case evaluated to be "true," the Token will flow into only the flow corresponding to the conditional expression, and conditional expressions written afterwards will not be evaluated at all. Thus, in case of XOR-Split, the Token will flow into only one flow. However, the marker notation in BPMN can not accurately explain that "the conditions are evaluated in order from the top one, and once one conditional expression is evaluated to be true, the conditional expressions afterwards will not be evaluated." Thereby, we must be careful enough to prevent participants from considering that all conditional expressions are evaluated just like OR-Split.

Related Articles

References

Toolbox
What links here
Related changes
Upload file
Special pages
Printable version
Permanent link
Questetra BPM Suite
Workflow Sample:Hints on Defining Workflows for Business Analysts and Managers.

Catetory
General nouns | Proper nouns | General-purpose business process | Core business process | Business process for support administration
Q-BPM This website was started by Questetra, Inc. for businesspeople all over the world, who are interested in BPM, but spend a great amount of time on the search of a lot of books, documents, and difficult terms. By saving the trouble of looking up a number of related terms or the time of searching documents, Questetra, Inc. hopes to contribute to businesspeople, interested in BPM, all over the world. Questetra Inc. Q-BPM exemplifies various Sample Processes regarding Business Flow in companies, and support Business Flow Diagram making. (* Business Flow Diagram: Business Flow Chart/Business Diagram/Business Process Diagram) This is Cloud-Source type information sending website that invites collaborators all over the world. In principle, contents in this website are public on the basis of the license called “CC-By SA,” which means “possible to copy under specific conditions.”

Powered by MediaWiki CreativeCommons By SA