At the core of the simulation and subsequent analysis is the 'macro system' under scrutiny. In practice, this comprises many self-sufficient systems (such as vehicles) operating with semi autonomous constraints. These systems are described be reference to their hierarchical structure and constituents. Failures within SIMLOXv2 contribute to events in both the operational and support network insofar as both critically and the associated support resources are modelled.

Scenario

The overall operational profile in SIMLOX is modelled by describing the Operational Support Organisation in the same terms successfully used by the OPUS10^TM model. SIMLOX models replacement tasks, repair tasks and the transportation of stock as separate activities each dependent on the availability and capability of key resources. Prior to each run, users may tailor the details modelled. For instance, precise stock allocations may be included and resources such as manpower, repair facilities, and specialised support equipment accounted for. Limited resources, which restrict the repair of specific failures, may also be targeted and monitored to determine whether they impact on system availability. Finally batch transportation, 'robbing', lateral resupply, scheduled maintenance and operationally induced damage may also be modelled.

Operational Simulation

A model run is performed against a profile, normally requiring a number of tasks (referred to as missions) to be performed by systems of the same or different types. Systems belong to units and several of these units based at a single operating site, of which may be modelled simultaneously. Units and systems are allocated a number of tasks to fulfil within the profile given imposed constraints (i.e. number of systems per task, task earliest/latest start times). Missions cannot start until all critical systems are serviceable and a mission success is dependent on the system reaching a predetermined point without incurring critical failure.

The system states within the simulation are preparation, ready, ready prepared, on mission, turnround and maintenance.

The simulation includes detailed mission definitions including:

• A mission can comprise several systems (vehicles/prime equipments)
• Minimum launch quantity
• Minimum delivery quantity
• Structured system failures initiate logistics activities
• Mission critical/non critical items
• Missions comprise a variety of 'sortie types'
• Adaptable success points
• Time on station facility
• Battle and maintenance induced failures

In the simulation a mission is defined as:

• An event that is scheduled to occur at a particular time and last for a defined period
• Ability to comprise a number of sorties i.e. several systems are required to undertake the same tasks at the same time
• In certain cases be permitted to proceed with less than the number os systems
• In certain cases be delayed by a specified time, called deferment time to allow systems that are still being repaired to become available

A mission can be split into 3 phases; outbound, on task and return. The outbound/ return times can zero or the on task time can be zero but not both. The simulation also has the capability for the modelling of regenerative missions. This capability will:

• Automatically programs missions to maintain on task time
• Ensures that new missions arrive on task when existing mission is about to return

This has the advantage of limiting gaps in on task time when system failure is critical.

Outputs

The output data files enable a wide range of Effectiveness Measures to be extracted. These include, but are not limited to, Operational Availability, Task Generation Rate, Critical Resource Shortages, Systems Redundancy and Probability of Operational Success. Multiple replications are performed to determine the cost-effectiveness of the support organisation in sustaining the operation. The model provides additional results including summary statistics giving confidence limits on output results. The user may select to automatically perform as many replications as required to achieve satisfactory target confidence levels.

SIMLOX Version 3 Enhancements
SIMLOX Version 4 Enhancements