Product(s):	LEGION Simulator
	Version(s):	CONNECT Edition
	Environment:	N/A
	Area:	Simulation Speed
	Subarea:	N/A

Problem Description

Are there any modelling workflow that can help to decrease Simulation time while handling very large models with high passengers attendance?

Steps to Accomplish

Here, are some modelling tips to help improve simulation speed.

Large areas with lots of demand and congestion will inevitably run more slowly than smaller, simpler spaces.  However, there are a number of things you can do to try and help the situation: 

• Minimize CAD complexity, especially Simulation and AutoNavigation CAD.  This will minimize the complexity of the navigation system and so run quicker.
• Try not to use Route Guides, as they are expensive to process.  If Route Guides are unavoidable, try and build them so that they filter for All entities, wherever possible.
• Try to build Percentage links, instead of Entity Choice and Final Destination links, as the latter are computationally more expensive.
• If you must use MultiPath Zones, limit their size and filter for as few entities as possible.
• If you must use Congestion Avoidance (leader/follower), try to limit the number of alternative targets and the distance to each, as longer paths mean more re-evaluations, which makes them longer to simulate.
• Try to be conservative with objects.  Avoid unnecessary duplication and overlaps, wherever possible.  More objects take longer to process and where objects overlap, entities must consider interactions with all overlapping objects that could affect them.  Overlapped objects can also cause model errors that can be difficult to resolve.
• If using Conditions, use Named Condition objects anywhere the same Condition is used more than once.  Also, try to minimize their complexity, wherever possible.  (Knowledge of Boolean algebra can be useful here.)
• Use standard Filters wherever possible.
• If using advanced Filters, minimize filter complexity.  (Again, knowledge of Boolean algebra can be useful here.)
• During simulation, turn off all CAD, world boundary, object, analysis, accessible space and entity displays.  Also, hide the output bar and timeline.  All drawing takes time.  Worst cases can be up to 15% of total simulation time.
• Use a dedicated desktop workstation with hardware configuration maximized.  Laptops tend not to be the most suitable environments for high performance mathematical simulations.  (See hardware recommendations, above.)
• When recording a RES file, save it to a different hard drive from the one on which Windows is installed, to prevent input/output competition with the Operating System.  (Also, use a high-speed drive, such as USB3.1, or Thunderbolt).
• When recording RES files or AVIs, don’t save them to a network drive and certainly not over Wi-Fi.  Network access is slower than local access and network Wi-Fi is inadequate for quick transfer of large quantities of data.
• In Simulator Tools->Options->Application Settings, change settings to maximize time between RES file writes:
  • In the “RES files” section, set “Number of frames to buffer before saving” to at least 100;
  • In the “Memory saving mode” section, un-tick “Activate”; and,
  • If the Legion metrics Discomfort, Frustration, Inconvenience and Dissatisfaction are not needed in your RES, un-tick “Include Legion metrics by default”.  Also, untick these options in the RES recording track’s properties on the Timeline.  Recording more data takes more time to write
• Lastly, try not to run other applications and shut down as many unnecessary background processes as possible.  Even on multi-core CPUs, the number of background processes vastly outnumbers the available processing threads.  So, anything that reduces overall computational load is worth doing.

Following these, where possible, will reduce simulation times, but don’t expect them to halve.  A good model built following these guidelines may run 10-20% faster, at best.