PS Agent TUM Calculations
- iarmstrong
The Alastri Production Scheduler scheduling engine is modelled around instantaneous time, meaning that it is possible to see what a piece of equipment is doing in every instant in time. APS lets users model periods of unproductiveness in two ways, Delays and Availability Types. Each method affects an Agent differently.
Delays
Delays are discrete events that can be recurring or a once-off. There are four possible delay states which are summarised in the table below.
Delay State | Flags | Description |
|---|---|---|
Available & Engine On |  | Duration of Delay will count towards Available Hours and Engine On Hours |
Available & Engine Off |  | Duration of Delay will count towards Available Hours and Engine Off Hours |
Not Available & Engine On | Duration of Delay will count towards Non-Available Hours and Engine On Hours | |
Not Available & Engine Off | Duration of Delay will count towards Non-Available Hours and Engine Off Hours |
The order of the delays is important. If there are overlapping delays, then the higher-ranked delay takes precedence and will be reported.
Because a delay has a known start and end time, when an Agent enters a delay, the agent will be unproductive for the duration of the delay. It is important to note that, unlike Availability Types, delays do not impact an Agents Productive Rate.
Availability Types
Availability types are calendar-based time usage factors that affect the productive hours of a piece of an Agent. The factors represent a duration of an Agents time where it is not doing its primary task. Because the start time and end time of these unproductive events are unknown, they all affect some portion of an Agents time and the Agents Productive Rate.
Availability Type | Description |
|---|---|
Unplanned Availability (UPA) | Affects the Productive hours and Available hours of an Agent |
Use of Availability (UA) | Affects the Productive hours and Engine On hours of an Agent. This should be the percentage of time the equipment could have been used but intentionally was not. |
Operator Efficiency (OE) | Affects the Productive hours of an Agent |
Productivity Factor (PF) | Affects the Productive hours of an Agent |
Note: These factors are applied after work schedule delays are set in the Work Schedule setup step. If an agent has 6 hrs of work schedule delays in a 12 hrs period, then the above factors apply to the remaining 6 hrs of the period.
Effect of Availability types on Agent Rates
Due to APS being based on instantaneous time, it is essential to know the time periods where downtime is occurring. With Availability events, the start time and duration are unknown, which causes complications within the instantaneous time paradigm. The two most logical solutions to model these availabilities within APS are outlined below.
Insert downtime events at random times throughout the schedule:
The duration of Availability events would need to be scattered throughout the period.
To implement properly would require Monte Carlo Simulation, which APS does not currently support.
2. Derate the Agent using the specified Availability factors so that the rate accounts for the periods of downtime. (This is the method that is used within APS)
Item | Calculation | Value |
|---|---|---|
Calendar Time | - | 12 hours |
Unplanned Downtime | - | 80% |
Use of Availability | - | 90% |
Operator Efficiency | - | 100% |
Productivity Factor | - | 100% |
Direct Utilisation | Operator Efficiency * Unplanned Downtime * Use of Availability * Productivity Factor Direct Utilisation may differ from your sites definition of Utilisation. | 72% |
Nominal Rate | Instantaneous dig rate | 3,750 t/hr |
Productive Rate | Nominal Rate * Direct Utilisation | 2,700 t/hr |
Total Mined | Productive Rate * Calendar Time | 32,400 t |
Reporting
Steady States
When we look at the individual Steady States (Steady States tab) , we can break down how Delays and Availability types are used. When it comes to reporting, report fields relating to TUM are just the aggregation of the individual Steady State fields during the specified time interval.
Steady State - Mining
Period Inputs | Value |
|---|---|
Unplanned Availability | 90% |
Use of Availability | 80% |
Operating Efficiency | 100% |
Productivity Factor | 100% |
Steady State Availability Fields | Calculation | Value |
|---|---|---|
Time.Duration | - | 2.0 |
Time.Agent Working Calendar Hours | Time.Duration - Delay Duration | 2.0 - 0 = 2.0 |
Agent.Utilisation | UPA * UA * OE * PF | 90% * 80% * 100% * 100% = 72% |
Time.Productive Hours | Agent Working Calendar Hours * Direct Utilisation | 2.0 * 72% = 1.44 |
Time.Engine On Hours | Agent Working Calendar Hours * UPA * UA | 2.0 * 90% * 80% = 1.44 |
Time.Engine Off Hours | Time.Duration - Time.Engine On Hours | 2.0 - 1.44 = 0.56 |
Time.Available Hours | Agent Working Calendar Hours * UPA | 2.0 * 90% = 1.8 |
Time.Unavailable Hours | Time.Duration - Time.AvailableHours | 2.0 - 1.8 = 0.2 |
Agent Nominal Rate | Instantaneous dig rate | 3800 t/hr |
Agent Productive Rate | Agent Nominal Rate * Agent.Utilisation | 3800 * 72% = 2,736 t/hr |
Steady State - Delay Marked as Available
Steady State Availability Fields | Calculation | Value |
|---|---|---|
Time.Duration | - | 0.333 |
Time.Agent Working Calendar Hours | Time.Duration - Delay Duration | 0.333 - 0.333 = 0 |
Agent.Utilisation | - | 0% |
Time.Productive Hours | Agent Working Calendar Hours * Direct Utilisation | 0 * 0% = 0 |
Time.Engine On Hours | Scheduled Delays Marked as Powered. | 0 |
Time.Engine Off Hours | Time.Duration - Time.Engine On Hours | 0.333 - 0 = 0.333 |
Time.Available Hours | Scheduled Delays Marked as Available | 0.333 |
Time.Unavailable Hours | Time.Duration - Time.AvailableHours | 0.333 - 0.333 = 0 |
Agent Nominal Rate | - | 0 |
Agent Productive Rate | - | 0 |
Period Reporting
By reviewing an individual Steady State, we can view the TUM metrics occurring at a point in time. Users can report and view period-based TUM metrics by looking in the Calendar or creating an Agents Report.
Calendar Fields
Several calendar fields report period based Availability values for Agents.
Field | Calculation |
|---|---|
Direct Utilisation | UPA * UA * OE * PF |
Engine Factor | OE * PF |
Agent Working Calendar Hours | Calendar Hours - Scheduled Delays |
Available Hours | Agent Working Calendar Hours * UPA + Scheduled Delays Marked as Available |
Engine Hours | Agent Working Calendar Hours * UPA * UA + Scheduled Delays Marked as Powered. |
Productive Hours | Agent Working Calendar Hours * Direct Utilisation |
Calendar Fields also exist, which summarise the Agents rate and the truck assignments over the duration of the period.
Field | Calculation |
|---|---|
Min Rate | The minimum instantaneous dig rate which the Agent operated at during the period. |
Max Rate | The maximum productive rate which the Agent operated at during the period. |
Average Utilised Rate | Quantity mined divided by the Agent Working Calendar Hours. |
Average Calendar Rate | Quantity mined divided by the Period Duration. |
Quantity | The total amount of material mined during the period |
Actual Max Instantaneous Trucks | The maximum amount of trucks assigned to the Agent during the period. |
Actual TUM Trucks | Truck Productive Hours divided by unit hours. |
For more information on setting the Сalendar, see PS. Calendar tab section.
Agents Report
In the Reporting tab, users can generate an “Agents” report to report Agent TUM data. Availability fields appear under both the “Agent” and “Time” folder.
For more information on setting the Pivot report, see PS. Pivot Tables section.