# Order of Operations

High-level order of operations followed by OSM during a simulation cycle; colors indicate the main controler of each process:

· Blue – OSM API;

· Green – OSM Variant;

· Yellow – OSM user commands.

# Preparing to Simulate

A number of steps are required to prepare the stand and trees for simulation from one cycle to the next as shown below.

When a stand-trees are loaded the stand is prepared for simulation before returning control back to the user; meaning all missing heights and crown ratios are filled, stand and tree compeitition metrics required by OSM or the Variant have been pre-calculated, and so on... as shown below. Many of these preparitory steps must be repeated before each new simulation cycle begins, and some steps must re-ocurr during simulation if harvest occurs.

Astricks denote operations that occur only once immediately following loading tree records for the stand and before the first simulation cycle.

Some of these operations depend on whether the Variant model has defined a grade and/or snag model and whether or not the user has defined genetic gain multipliers or height calibration; if not defined, then those operations do not occur.