The Process Chart diagram offers two line symbol types to model flows – the Mandatory Sequence line and the Optional Sequence line.
Mandatory Sequence Line
A Mandatory Sequence line is used to model the fact that the flow must be taken. The Mandatory Sequence line has a solid black arrowhead. A grouping of Mandatory Sequence lines is used to model an AND condition, either on fan-out or fan-in to a process (see below).
Optional Sequence Line
An Optional Sequence line is used to model the fact that the flow can be taken (it is optional). A grouping of Optional Sequence lines is used to model an OR condition, either on fan-out or fan-in to a process (see below). Additional properties can be set for this type of line (for example, probability or priority of the flow being taken) when Simulation properties are turned on.
Modeling complex logic
In the Process Chart diagram, logical fan-in and fan-out gates are modeled using a combination of Optional and Mandatory Sequence lines.
AND: On fan-in to a process, AND logic denotes that all signals must be present for the process to begin. On fan-out, AND logic denotes that all signal paths are taken. To model an AND condition, use two or more Mandatory Sequence lines.
AND Logic
Inputs
A
0
0
1
1
OR: On fan-in to a process, OR logic denotes that either of two signals must be present for the process to begin. On fan-out, OR logic denotes that either signal path is taken. To model an OR condition, use two or more Optional Sequence lines.
OR Logic
Inputs
A
0
0
1
1
XOR: The XOR acronym stands for Exclusive OR – one or the other signals must be present, but not both. To model XOR logic, use two Optional Sequence lines, and set an exclusive arc character for each – the exclusive arc character must be the same for each grouping. The exclusive arc character can be any character or set of characters.
