Upload
manuel-aragon
View
220
Download
0
Embed Size (px)
Citation preview
8/12/2019 iGantt Optimizer Tutorial for OpenPit
1/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 1of 19
Minemax Tutorial
iGantt
Optimizer
for
Open Pit
Version: 4
Updated: May 2013
8/12/2019 iGantt Optimizer Tutorial for OpenPit
2/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 2of 19
COPYRIGHT NOTICE
2013
Copyright in this document is vested in Minemax Pty Ltd.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
3/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 3of 19
1. INTRODUCTION
1.1 PurposeThe purpose of this tutorial is to demonstrate the use and the functionality of iGantt
Optimizer for short-term up to long-term detailed scheduling for Open Pit applications.
2.1 Prerequisites
The prerequisite knowledge for this tutorial is an intermediate level of proficiency using
iGantt software to:
Create an iGantt project (attributes, activity types, calendars, report items and
reports)
Load visualization from strings and triangulated surfaces and format the 3D view
Import and map activities
Create precedences for activities
3.1 Scenario
The scenario used for this tutorial is an open pit project for basic load and haul activity
scheduling with locations within multiple pits, pushbacks, and benches down to the flitch
level.
The aim of this project is to generate a long-term schedule with 36 time periods by
maximizing the profit of the project (Net Present Value) while satisfying all mining and
processing capacity constraints.
The total material mined has a fixed truck capacity constraint of 25,000 truck hours per
month. The processing plant has a fixed capacity of 1.5M tonnes per month.
The duration of the time periods varies over time with 1-month increments for the first year,
3-month increments for the following 3 years and yearly increments for the remaining time
periods.
Apart from the standard location and physical attributes such as ore tonnes, waste tonnes
and grades, the revenue, mining and processing costs and truck hours are modelled in this
scenario.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
4/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 4of 19
2. TUTORIAL STEPS
1. From your Windows Start menu, click All Programs iGantt Tutorials
Tutorial Files Optimizer OpenPit to navigate to the tutorial filedemotutorial_iGantt_Optimizer_OP.igt. Double-click on the file to load the project into
iGantt displaying activities, 3D visualization and the default report on a single screen. TIP:If you are a Windows 8 user, right-click the Windows Start screen to view thebottom bar with the All Apps icon. Click on the All Apps icon and then click
Tutorial Files Optimizer OpenPit to navigate to the tutorial filedemotutorial_iGantt_Optimizer_OP.igt.
2. Click the Project menu and then select Project Attributes to view attributes
previously defined for this project. Click the OKbutton to exit.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
5/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 5of 19
3. Click the Project menu and then select Activity Types to view activity types
previously defined. In this project, we are using one activity type LH (LoadHaul).
TIP: Other activity types such as Drilling or Blasting can be also modelled if
desired.
4. Click the OKbutton to exit.
5. Click the Project menu and then select Edit Project Calendar to view the currentproject calendar. The iGantt Optimizer requires the default calendar 24 hours, 7 days
with no non-default days.
6. Click the OKbutton to exit.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
6/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 6of 19
TIP: If a non-default project calendar is detected by iGantt Optimizer, a warningmessage will appear with the option to remove all non-default days or times byclicking the Fix Schedule Automaticallybutton.
7. Click the Resources menu and then Edit Resources to view the Resources
window. In this project, no resources are set up as we will create an activity-based
schedule.
8. Click the Closebutton to exit.
9. Click the Reports menu and then Define Reports to view details about the
Summary report by selecting the EditReportbutton. The Summaryreport includes
summary items for Ore Tonnes, Au Grade, Waste Tonnes, Total Tonnes, Trucks and
Financials per time period.
10. Click the OK button to exit.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
7/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 7of 19
11. Click the Optimizermenu, select Optionsand then click the Time Periodssub-
menu to specify the time periods for the optimization.
11.1. To add variable optimization periods, click the Edit in Advanced Mode button.
11.2. Change the start time to show 01/07/2013 and then enter the value 36 into the
Number of Time Periods field.This will generate 36 time periods.
11.3. Change the Increment value to month for the first period. Then click the
Copy Forwardbutton.
11.4. Scroll down to Period 13 and change the TimeAmount valueto 3. Then click
the Copy Forward button.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
8/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 8of 19
11.5. Scroll down to Period 21 and change the Time Amount value to 1 and the
Increment value to year. Then click the Copy Forwardbutton.
12. Click the Constraints sub-menu to add constraints for our project. In this scenario, we
will constrain the milling process using the OreTonnesattribute and the mining process
using the TruckHoursattribute.
TIP:If cycle times are not available for the truck hours calculation, the total tonnes
can be also used to constrain the mining process.
12.1. Click the New button to add a new constraint. This will open up the Add
Constraint window displaying the Details sub-menu.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
9/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 9of 19
12.2. Type the name of the constraint Milling in the Name field and select the
constrained attribute OreTonnes from the drop-down menu.
12.3. Click the Activity Typessub-menu to select the activity type that will be
constrained. Click the LH (LoadHaul) activity on the left and move it across to
the right area by clicking the > button. Then click the OK button.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
10/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 10of 19
12.4. This will create two entries for minimum and maximum milling constraints per
time period. Enter the maximum value of 1,500,000 tonnes into the monthly
time periods, 4,500,000 tonnes into the quarterly time periods and 18,000,000
tonnes into the yearly time periods.
TIP: Use the Copy Row Forward button to copy the required value to all
subsequent time periods.
12.5. Repeat steps 12.1 to 12.4 to add the TruckHours constraint to the grid.
12.6. This will create two entries for minimum and maximum truck hour constraints pertime period. Enter the maximum value of 25,000 hours into the monthly time
8/12/2019 iGantt Optimizer Tutorial for OpenPit
11/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 11of 19
periods, 75,000 hours into the quarterly time periods and 300,000 hours into
the yearly time periods.
13. Click the Options sub-menu to select the optimization strategy from the three
available options:
Forward schedulingoptimizes one period at a time, carrying results from one period
forward to the subsequent period. This option provides a very fast result but doesnt
guarantee finding the theoretically optimal schedule.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
12/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 12of 19
Global schedulingconsiders all time periods together and can find the true optimal
schedule. If a large number of blocks and time periods are used, global scheduling
can be quite time consuming.
Sliding window schedulingoptimizes x time periods at once and then moves y
time periods forward. The same process repeats in multiple interactions defined bythe x + y combination where x represents a sliding window lengthvalue and y
represents a sliding window stepvalue. This gives a balance of solution time and
solution optimality.
13.1. Tick the Sliding window scheduling option. By default, the 2+1 option is
selected. This means that two time periods are optimized at once. After
completing an optimization phase, the result for the first time period is kept and
the window is moved forward by one time period to optimize the next two time
periods. This process repeats until the schedule for the last time period is found.
13.2. Confirm that the Reset rates to defaults option is ticked. This option will replace
any manually added activity rates with the default rate which has been set for the
activity type.
13.3. Confirm that the Adjust rates to fit periods option is ticked. If your target is not
reached within the time period set while using the default rates, this option will
increase the rate to ensure the target value is reached within the specified time
periods.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
13/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 13of 19
13.4. Select the attribute Profit from the Value drop-down menu. By doing so, iGantt
Optimizer will optimize the schedule by maximizing the profit of the project.
13.5. Click the OKbutton.
13.6. The attribute Profit is a calculated attribute that has been previously defined
under Project Attributes by selecting the Project menu.
TIP: Other attributes can be used as a Value parameter as required. For
example, if Ore Tonnes are used, iGantt Optimizer will optimize the schedule by
maximizing ore tonnes for the project.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
14/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 14of 19
14. Click the Optimizermenu and then click Optimize. This will open up an Optimize
window showing the first and last periods to optimize. The dates of the first and last time
periods flow through from the Time Periods sub-menu set up previously.
TIP: Tick the Apply tick-box if you need to change the first or last period to
optimize.
15. Click the Optimizebutton. This will activate the optimization showing a dialog window
with the progress bar. The iGantt Optimizer uses a mixed integer linear programming
(MILP) model to represent the mine and its production constraints using a branch and
bound algorithm.15.1. In the first step, the dialog window displays the Initializing message while
iGantt Optimizer builds the mathematical model of constraints.
15.2. In the second step, the dialog window displays the Periods 1-2: Still looking for
resultmessage. This means that the maximum upper value (bound value) withinthe first two time periods is being searched for.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
15/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 15of 19
15.3. In the next step, once the bound value is determined, iGantt Optimizer looks for all
possible feasible solutions within the first sliding window and compares them
against the bound value.
15.4. The message Result found within 14.59% means that the best feasible solution
so far is at most 14.59% from optimality. The iGantt Optimizer will keep looking forall other solutions until a solution within 1% is found.
15.5. In the next step, the sliding window will move to the next period and repeat steps
15.2 to 15.3. When the best solution for the last optimization period is found, the
dialog box will disappear.
TIP: It takes approx. 8 seconds to optimize the project using sliding window
scheduling with the 2+1 option. The optimization time will vary based on the
optimization method selected and the number of blocks and constraints in your
project.
16. The Summary Report shows total values for each report item per time period. The Ore
Tonnes and Truck Hours items meet the maximum constraint per time period set in the
Optimizermenu.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
16/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 16of 19
17. Click the Visualization menu and then select Set Object Colour Scheme.The
Colour Scheme Chooser window will open upand display the default mode of Colour
By Object Type.
17.1. Select Colour By Time Period from the drop down menu to change the colouring
mode to time periods
17.2. Tick the Repeat Colours tick-box to repeat the same colours every eighth time
period
17.3. Tick the Multi-Time Period Object Colouring tick-box to splits strings into the
multiple coloured sections
17.4. Tick the Show in Summary Report tick-box to show the colouring code in the
Summary report
17.5. Click the OKbutton. This will display the colouring mode in the visualization as
well as in the reports.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
17/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 17of 19
18. Click the Visualizationmenu and then select View Scheduleto validate the
schedule using an animation.
18.1. Tick the Show Remaining tick-box to step through the remaining reserve.
18.2. Select the viewing date of 01/07/201318.3. Select the time interval of 256 ms and then click the Run button
19. The animation steps show the progress of load and haul activities by showing the
remaining reserve for the date of 12/12/2016.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
18/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 18of 19
20. The animation shows some remaining material that has not been scheduled within the
optimization periods due to economics and precedences included in this scenario.
.
21. Load the iGantt file demotutorial_iGantt_Optimizer_OP_optimised to compare your
results.
8/12/2019 iGantt Optimizer Tutorial for OpenPit
19/19
Minemax Tutorial iGantt Optimizer for OP Minemax 19982013 Page 19of 19
3. SUMMARY
This tutorial has shown you the necessary steps to develop a long-term schedule usingiGantt Optimizer.
In the first steps, we reviewed project attributes, activity types and reports previously set upin the iGantt project provided.
Secondly, we showed you how to set up 36 time periods of variable lengths to be used forsetting constraints and optimizing.
In the next step, we showed you how to set up a processing constraint using ore tonnes anda mining constraint using truck hours for each time period.
In the following step, we discussed optimization options and showed you how to set up thevalue parameter that is used for optimizing. In this scenario, we were maximizing the NetPresent Profit value of the entire project.
Once the optimization was completed, we also showed you how to set the object colourscheme per time period and analyze results using reports and animations.
Congratulations on completing the iGantt Optimizer tutorial for Open Pit applications.
Please contact our Minemax experts on [email protected] for additional informationabout iGantt Optimizer.
mailto:[email protected]:[email protected]:[email protected]