OPSIM is a general purpose operational simulation tool for the expert modelling of both natural and industrial water resource systems. It provides a powerful and flexible platform for attaining a quantified insight and understanding of a system's performance - historical, current and possible alternative future - under a comprehensive array of climatic conditions. The software provides the User with an extensive array of predefined components with which to build a simulation model, sufficient to define both simple and complex water systems alike.
OPSIM is the foundation platform onto which extensions provide enhanced specialist functionality (Geochemistry and Adaptive Real-time Simulation extensions). It is expert system type software, designed by expert water engineers, to allow users to focus on problem solving and not on the intricacies of simulation model creation. It has been developed to provide the user with the means to rapidly and reliably create operational simulation models with relative ease. Inbuilt graphical plotting and numerical analysis allows rapid quantification and visualization of simulation outcomes, with full access to copy and paste into other applications for reporting and other analysis.
Although OPSIM is typically used for industrial and mining water management activities, it is also equally well suited to the assessment of water supply reservoir yield, the assessment of multiple operating strategies, and water resource planning.
Accurate estimation of rainfall generated runoff from catchments commanded by a water management system is a fundamental requirement for a water resources modelling system.
OPSIM provides users with a library of alternative methods for runoff estimation, to suit the needs of individual preferences. Multiple sets of land-type parameters may be defined for application on a sub-catchment basis to provide a high level of spatial resolution.
Multiple contributing rainfall station data can also be specified for larger catchment areas, with sub-catchment level weighting for proportional distribution. An option is also included to allow for "rain day" preservation on those catchments with multiple rainfall station contribution.
Antecedent rainfall often plays an important role in the rainfall-runoff process, particularly in the initial period of a simulation run. OPSIM provides support to overcome this modelling problem by automatically "pre-running" hydrology components within a model. This technique properly initialises catchment conditions prior to commencement of the simulation proper.
Mining operations usually include some form of tailings dam. Containment of contaminated water within a tailings dam if often of key importance to an operation.
The accumulation of tailings within a dam will reduce its capacity to store free water, and over time this will result in an ever-increasing risk of overflow, unless preventative action is taken. Typically, this risk of overflow is primarily associated with the occurrence of rainfall that is captured within the storage over a period of time.
A common use of OPSIM is to inform water management system operators of the likelihood of occurrence of certain circumstances at a future date — such as tailings dam spill, for example. OPSIM's forecasting capabilities are perfectly suited to this application, and provide operators with a substantiated basis for risk based decision making.
Of course, the other application of these same techniques is for the initial sizing of tailings storages (or their raising) to meet with both tailings and free water containment requirements, over a prescribed period of time.
The linked scenario feature allows multiple simulations to be connected in time regardless of the number of changes to operating rules and nodes. This function makes OPSIM capable of seamlessly simulating changes in operational procedure, and capable of exploring a wide range of future possible operating parameters. This feature is particularly suited to life-of-mine planning where contaminated water inventories may need to be managed for a considerable period of time.
Every model created in OPSIM has a unique ID associated with it so documents can be tracked. Models can also be locked, turning them into a mastered document. Mastered documents are encrypted, and only the simulation dates and outputs can be modified, with all other simulation parameters being locked. This means that once a validated model is created it can be locked and distributed as a controlled document, and other users can use that model and be certain that it has not been modified.
Due to OPSIMs powerful computational engine, it can be used to perform and post process multiple types of analysis from a single system model. These tasks include model calibration, which is made easy through the analysis interface; time series analysis, which can be performed to generate statistics at different time resolutions; event based analysis using system simulation triggers, such as spill events; and statistical analysis to calculate annual exceedance probabilities (AEP) or percentage of time (POT) plots.
OPSIM implements Water Accounting Framework (WAF) requirements for the quantification of the operational efficiencies of specified tasks within a modeled water management system. This is undertaken through the assignment of water quality based categories to the various inflow streams to the tasks. Assessment of operational efficiencies is made by tracking water category flow volumes through the course of simulation. Reporting includes comprehensive account of all water inventories entering, leaving and retained within each task of the water management system under assessment.
OPSIM's WAF implementation of operational efficiency and reporting calculations are in alignment with the framework for the Global Reporting Initiative (GRI, Amsterdam 2010) as applied by the Mineral Council of Australia (MCA, 2014).