Discrete Event Simulation Models (DES)

Model What Happens Next—and When It Happens

TreeAge Pro lets you simulate individual patients in continuous time, with events occurring according to their time-to-event distributions rather than at fixed model cycles.

  • Model competing events by sampling when each event may occur and determining which happens next.
  • Represent event timing in continuous time using time-to-event distributions.
  • Track patient events and history as individuals move through the simulation.
  • Accumulate costs, utilities, and other outcomes as time passes and events occur.

Build DES Models Visually

Build event pathways in TreeAge Pro’s visual modeling environment, using DES and Time nodes to represent how individual patients move through the model as events occur.

Define Possible Events
Create branches for the competing events that can occur as patients progress through the model.

Represent Event Timing
Use Time nodes to determine when competing events occur and which event happens next.

Start from an Existing Markov Model
Convert an existing Markov model into an initial DES structure, then add the time-to-event expressions and other DES-specific logic needed for the simulation.

Model Competing Events in Continuous Time

Represent events based on when they occur rather than using fixed model cycles.

Model Competing Events
Define the events that can occur next and sample a time-to-event for each. The event with the shortest sampled time occurs next.

Use Time-to-Event Distributions
Use parametric distributions to represent when events occur and how event risk changes over time.

Account for Prior Events and Time
Use conditional sampling when the timing of future events depends on elapsed time or what has already happened to the patient.

Track Events, Time, and Outcomes

Track what happens to individual patients over time and accumulate outcomes as events occur.

Track Patient Events and History
Retain information about prior events so patient history can influence what happens later in the simulation.

Model Repeating Events
Represent events that can occur multiple times during a patient’s simulated lifetime.

Accumulate Costs, Utilities, and Other Outcomes
Apply outcomes as events occur or accumulate them over time, allowing costs, utilities, and other measures to reflect each patient’s experience throughout the simulation.

Analyze and Validate Your DES Model

Run Discrete Event Simulation to examine individual patient experiences and evaluate results across the simulated population.

Explore Patient and Population Outcomes
Review individual patient pathways and event timing, then aggregate results across the simulated population to evaluate costs, effectiveness, and other outcomes.

Analyze Cost-Effectiveness and Uncertainty
Use TreeAge Pro’s integrated analysis tools to evaluate cost-effectiveness and explore the impact of uncertainty in model inputs and assumptions.

Inspect and Validate Simulation Behavior
Use patient tracking and simulation reports to examine event timing, patient history, calculations, and outcomes and understand how the model produces its results.

Communicate and Share Your Model

Use the visual model and reports to explain model structure, event pathways, assumptions, and results.

Share models through TreeAge Pro Web so others can explore inputs, analyses, and results.