5.4.2 Linking Activities

Linking two activities deployed on the canvas defines a business process execution sequence.

Organization of this subsection
(1) Link types
(2) Link setting method
(3) Changing links
(4) Bending linking lines
(5) Conditions for linking activities
(6) Notes on using connections

(1) Link types

The following types of links can be used for activities:

How the linking line is displayed on the canvas differs depending on the linking method. The following table describes the relationship between linking methods and linking lines.

Table 5-1 Linking lines displayed on the screen

Linking methodLinking line displayedLine colorLine typeTermination
Link based on connection[Figure]BlackSolid lineTriangular arrow
Link based on fault connection[Figure]RedBroken lineTriangular arrow
Link based on link connection[Figure]BlueDotted lineLine arrow

(2) Link setting method

To link activities:

  1. On the palette, click Connection, Link, or Fault.
    Connection, fault connection, or link connection is selected.
    In this state, move the cursor to an activity. If that activity can be specified as a link source, its background color changes.
  2. From the activities deployed on the canvas, click the activity that is to become the link source.
    The activity that is to become the link source is set.
    In this state, move the cursor to another activity. If that activity can be specified as a link destination, its background color changes.
  3. From the activities deployed on the canvas, click the activity that is to become the link destination.
    The link-source and link-destination activities become linked.

(3) Changing links

To change an already specified link, drag and drop the starting point or termination point of a linking line into another activity.

(4) Bending linking lines

You can bend and display linking lines. You can use this operation to rearrange the linking lines on the canvas when the links among activities become complex. The method for bending linking lines is described as follows:

  1. On the canvas, select a linking line.
    Points at which the linking line can be bent (bend points) are displayed between the starting and termination points of the linking line.
  2. Align the pointer of the selection tool to a bend point.
    A cross-shaped arrow ([Figure]) appears.
  3. Drag and drop the arrow into any position.
    The linking line bends at the bend point.
    On a linking line that has been bent at a bend point, the following positions can also be used as bend points:
    • Between the starting point of the linking line and the bend point
    • Between the bend point and the termination point of the linking line
    • Between the bend point and another bend point

(5) Conditions for linking activities

Whether an activity can be used as a link source or link destination differs depending on the type of activity and the link used. The following table describes activities that can or cannot be used as link sources or link destinations.

Table 5-2 Activities that can or cannot be used as link sources or link destinations

ActivityConnectionFault connectionLink connection
Link sourceLink destinationLink sourceLink destinationLink sourceLink destination
StartY----------
ReceiveYY--YYY
ReplyYY--YYY
Invoke serviceYYYYYY
Invoke JavaYYYYYY
Data transformationYY--YYY
AssignYY--YYY
EmptyYY--YYY
Throw--Y--YYY
StandbyYY--YYY
ValidateYY--YYY
ScopeYYYYYY
WhileYY--YYY
Switch (Start)YY--YYY
Switch (End)YY--------
Flow (Start)YY--YYY
Flow (End)YY--------
End--Y--------
Legend:
Y: Activity can be used as a link source or link destination.
--: Activity cannot be used as a link source or link destination.

When activities are linked through a connection, an activity that becomes the transition source to another activity is called a transition-source activity, and an activity that becomes the transition destination from another activity is called a transition-destination activity.

The number of transition-source activities and transition-destination activities that can be linked using a connection (excluding fault connections and link connections) varies according to each activity.

The following table describes the number of transition-source and transition-destination activities that can be linked for each activity.

Table 5-3 Number of transition-source and transition-destination activities that can be linked

ActivityNumber of transition-source activities that can be linkedNumber of transition-destination activities that can be linked
Start01
Receive11
Reply11
Invoke service11
Invoke Java11
Data transformation11
Assign11
Empty11
Throw10
Standby11
Validate11
Scope11
While11
Switch (Start)11 or more
Switch (End)1 or more1
Flow (Start)11 or more
Flow (End)1 or more1
End10
Note
A receive activity that generates instances is the only basic activity that can be executed first in a business process.

(6) Notes on using connections