Model 2 - Parallel Gateways

Goals of this lesson

• Getting to know how the semantics of the parallel gateway work

How-to

This model shows a business process with parallel gateways. When the sequence flow hits a branching parallel gateway, it starts a sub-process for every outgoing link

Figure 1. Model 2 - Parallel Gateway / IYOPRO-Link

Explanation

• In the model (in the illustration above) the first gateway starts two sub-processes (or analogical two tokens will be send on the path), that will be merged in the second gateway.

 The merging gateway will not fire until both sub-processes (tokens) have arrived.
• Model 2 defines a constant duration of 4 time units (TU, hours in this case) for the upper activity and a constant duration of 1 TU for the lower activity.

• This means, the bottom sub-process has to wait 3 TU until it is merged by the gateway.

• The total lead time (or processing time) of the business process will always be 4 TU.

Report

See below for the run configuration, which we set up to receive the report statistics from below.

Run configuration

• Stochastic Seed: 12345

• Simulation start date: 1/1/2014 12:00:00 a.m.

• Simulation stop time: 240

• Simulation stop time unit: Hours

Report statistics

• As you might notice, the process cycle time is always 4 hours

• There is no standard deviation because we set up constant durations for both activities

• And as mentioned before, this model’s process cycle time depends on the activity with the longest duration

• The merging parallel gateway has to wait for all sequence flows to arrive

• That is why the process cycle time is always 4 hours, which is the top activity’s duration

• Also note: The box-plot from Figure 2 below is nearly invisible.

• It is reduced to a simple line, because all the statistics are equal (Min-, Max-value, etc.)

Figure 2. Process cycle times of Model 2