Scheduler Tutorial

This tutorial will introduce and familiarize you with the basic functions and features of STK Scheduler; you will start the STK Scheduler software application, specify a planning period, define various tasks and the resources that they require, import access data and event reports from STK to help define task scheduling opportunities, and solve the scheduling problem using the available deconfliction and optimization algorithms. In addition, you will exercise the various controls for on-screen schedule viewing and generate task and resource-based reports. This tutorial generally takes approximately one and a half hours to complete.

This tutorial requires that you have STK Scheduler installed and licensed (version 11.0 or higher). STK version 11.0 or higher (free version minimum) is also required for this tutorial. Contact Orbit Logic or Analytical Graphics for free software evaluation licenses.

If you would like additional information about any of the options and fields on any STK Scheduler form as you go through this exercise, please use the form-specific STK Scheduler HTML Help available by clicking on the button on any form.

Setup

Launch STK Scheduler.
Save the schedule.

Select File > Save As
Browse for the directory where you want to save the schedule.
Enter the filename "STKscheduler Tutorial".
Click Save.

STK Scheduler works with schedule files, similar to the way Microsoft Word works with document files. Everything about a scheduling problem (including its solution) is saved in a schedule file.

Associate the schedule with an STK scenario.

Select Schedule > STK > Load Scenario
Click Change Scenario.
Select the Tutorial.vdf scenario file from the following folder: <STK install folder>\STKScheduler\Examples\Scenarios\Tutorial

The default STK install folder is C:\Program Files\AGI\STK 12.

Click OK.

Associating the schedule with an STK scenario allows you to apply STK objects and reports to the scheduling problem. STK Scheduler will start STK and load the selected scenario. After the STK application starts and the scenario loads, you can minimize the STK application window or bring the STK Scheduler form to the front.

Define the schedule start and stop times.

Select Schedule > Define Start/Stop
Set the Start Time to 2022/01/01 00:00:00 and the Stop Time to 2022/01/03 00:00:00
Click OK.
Verify that the STK Scheduler software has updated the STK scenario times to match the schedule start/stop times.

In STK, right-click on the Tutorial scenario object in the STK Object Browser
Select Properties
Verify the scenario start and stop times
Close the Basic Properties window and minimize the STK window.

The schedule file schedule time period is shown in the lower left corner of the main STK Scheduler form at all times.

Defining Resources from STK

STK Scheduler solves task scheduling problems related to limited resources. Before tasks can be defined, the resources that they require must be defined. This portion of the exercise defines six resources that will be used as resource options to support the tasks defined in the next section of the exercise. Expect this section of the tutorial to take about 40 minutes to complete.

Define a single resource from STK, such as the AQUA resource.

Select Resource > New Resource.
In the Resource ID field, enter "AQUA".
Click Browse STK Objects and select the AQUA satellite object.
Click OK.

This will associate the AQUA resource in the STK Scheduler schedule file with the AQUA satellite object in the associated STK scenario for the purposes of access calculations and event reports.

Click Update then Close.

You will see the resource listed in the resource availability section at the bottom of the Gantt view window. The teal-colored bar to the right of the resource name shows the resource availability against the schedule timeline. The line is solid since we accepted the “always available” default definition for resource availability. Note that this availability is for the resource in general and does not intend to represent STK accesses or other task-specific constraints that will be applied later in the work flow.

Ingest multiple resources from STK.

Select Resource > Ingest from STK and select All.
Select the following STK scenario objects from the list:

Scenario/Tutorial/Facility/Goldstone26
.../Facility/Guam46
.../Facility/Madrid26
.../Star/CassiopeiaStar_HR-21
.../Target/AmazonTarget

Click OK.

Each of the new resources has been added below the AQUA resource at the bottom of the STK Scheduler Gantt view. All of these new resources have default attribute values and are associated with their applicable STK scenario object.

Edit Resource Attributes

Edit Madrid26.

Right-click on the Madrid26 resource and select Edit Resource.
On the General tab set the "Setup Time" to 10 minutes.

Setup time reserves the resource for a period of time prior to a task's assigned time in the schedule. Resource setup can occur prior to a task timeslot.

Select the Availability tab.

The "Define Blackout Times – Default Available" option is selected, which means any windows defined on the resource are blackout periods.

Select the Discrete Windows tab and click Add.
Set the following properties on the new window:

Window Start: 2022/01/02 06:00:00
Window Stop: 2022/01/02 12:00:00
Comments: Antenna Maintenance

Click OK.

The blackout period is now listed in the Availability windows list for this resource.

Click Update, then Close.
Verify availability changes for Madrid26.

In the STK Scheduler Gantt view, select View > Timescale View Properties
Select "five_minutes" for the Scale and click OK.

The white area in the Madrid row indicates that the resource is not available for use during that time period which you just defined.

Change the priority of Guam46.

Right-click on the Guam46 resource and select Edit Resource.
On the General tab set the Priority to 8.
Click Update.

This will make the Guam ground station a lower priority than Goldstone or Madrid since both are still set at the default priority value of 5 (middle of the 1-10 default range). The deconfliction algorithms take resource priority into account when multiple resource options are available for a task. Changing Guam to a priority of 8 essentially makes Guam a backup to Goldstone and Madrid (it is a less desirable assignment). Global resource priorities can be overridden on a task-by-task basis.

By default, the priority range is 1 - 10, with 1 being the highest. You can configure the range and convention for task and resource priority schemes under the Schedule > Properties menu, Task Priority and Resource Priority tabs.

Use an STK report to specify availability for AmazonTarget.

Select the AmazonTarget resource.
Go to the Availability tab.
Select the "Define Availability Times – Default Unavailable" option.
Select the Discrete Windows tab and click on STK Import.

The STK Report Definitions form will appear, and will be blank because you have not defined any reports yet.

Click Add to bring up the Define STK Time Report form.
Select the "Sun" Report Type and "AmazonTarget" for STK Object 1.
Click OK to accept the report definition.
Click OK again to confirm that this is the only report to apply.
Click Update

Confirm that the target sunlight windows for the defined two-day period are returned in the Availability windows area. Note that these sunlight windows were retrieved from STK.

Click Update and Close.

The Amazon resource now has two defined availability periods (colored teal bars on the Gantt view) corresponding to the times when it is in the sun.

Change the accommodation of AmazonTarget and CassiopeiaStar_HR-21.

Some resources, especially passive resources like targets, are often best defined as having Unlimited Accommodation (ie. they never get “used up”).

Right-click on the AmazonTarget resource and select Edit Resource.
Go to the Accommodation tab.
The accommodation is already set to Unlimited Accommodation for both AmazonTarget and CassiopeiaStar_HR-21.

As a default, resource Accommodation for Stars, Planets, Point Targets, and Area Targets ingested from STK (using the Resource > Ingest from STK function or via the API) is set to Unlimited. For all other STK object types and for all resource definition through the GUI (Resource > New) regardless of STK object type, default accommodation is 1.

Click Update and Close.

Defining Non-STK Resources

We are going to define two more resources: a mission operations team and an onboard solid-state-recorder (SSR), which are not associated with any STK objects. STK Scheduler is not limited to STK resources; any kind of resource can be defined and used as a task requirement. The SSR resource will help demonstrate the use of the resource capacity attribute in task scheduling.

Define the OpsTeam resource.

Select Resource > New Resource.
In the Resource ID field, enter "OpsTeam".
Go to the Availability tab
Select the "Define Availability Times – Default Unavailable" option.
Select the Periodic Windows tab and click on Add.

You can use periodic windows to define the times during which the OpsTeam will be available (when the controllers are in the control center), especially if the times are the same every day.

For Frequency select "Daily".
Click Add.
Set the following properties on the new sub-window:

Window Start Offset: 08:00:00
Window Duration: 4 hours
Comments: Morning Shift

Click OK to apply the sub-window.
Click Add again to define another sub-window.
Set the following properties on the second sub-window:

Window Start Offset: 13:00:00
Window Duration: 4 hours
Comments: Afternoon Shift

Click OK to apply this second sub-window.

Window start offsets are measured from the Period Start Time for the recurring definition.

Two sub-windows are now defined in the Periodic definition for the OpsTeam. These morning and afternoon shifts will be applied each day of the planning period based on the defined Period Start Time and Period Stop Time.

Click OK to apply the daily periodic window.
Select the Accommodation tab.

The default accommodation is 1. Accommodation is the number of simultaneous tasks that can be supported by the resource.

Change the Maximum Accommodation to "2".

This indicates that the OpsTeam resource can support up to 2 tasks simultaneously. For example, this will allow the OpsTeam to write a report and support a satellite contact at the same time.

Click Update and Close.

On the Gantt, the OpsTeam resource's expected shift times are shown as teal-colored bars (2 pairs of 4-hour periods, 1 pair for each day).

Define the SSR resource.

Select Resource > New Resource.
In the Resource ID field, enter "SSR".
Go to the Capacity tab.
Select the Is Applicable checkbox.

Capacity is not applicable to all resources, just those that have capacity that can be depleted or replenished (like a recorder).

In the Units field, enter "Mbytes".
Under Capacity Type, select "Consumable".

Consumable capacity means that resource's capacity is permanently depleted (or replenished) by a task. The alternative, Resilient, means that resource's capacity is depleted/replenished only for the duration of the task.

Set the following properties for Capacity Limits:

Maximum Capacity: 100
Minimum Capacity: 0
Initial Capacity: 100

Select Soft next to Maximum Capacity.

A soft capacity limit is a limit that does not have the power to prevent a task from receiving an assignment. If the action of replenishing capacity will cause the capacity value to exceed a soft limit, the task will be assigned, however, the instantaneous capacity value will freeze at the soft limit.

Click Update and Close.

You have now defined eight resources for use in this schedule file: 3 ground facilities (Madrid, Goldstone, and Guam), 1 satellite (AQUA), an operations team (OpsTeam), a ground target (AmazonTarget), a star (CassiopeiaStar_HR-21), and an onboard recorder (SSR). Madrid, the ops team, and the ground target have limitations on their availability specified.

Now is a good time to take a break and stretch your legs. Select File > Save to save your work if you have not done so already. After your break, continue on with the Defining Tasks section to define and deconflict tasks that use the resources you have defined here.

Defining Tasks

In this section you will define 5 separate tasks with differing constraints and resource requirements including:

Expect this section to take about 20 minutes to complete.

AQUAcomm Task

AQUAcomm is a recurring satellite to ground station communications task.

Select Task > NewTask
In the Task ID field, enter "AQUAcomm".
Go to the Scheduling tab.
Select the radio button next to Recurring Task.
Choose Time under Scheduling Windows Defined by.

You will see a pair of tabs at the bottom of the window that allows you to define the time-based recurring nature of the task.

Select the Periodic Windows tab and click Add.
Set the Frequency to "Daily"
Set the Repeat Type to "Per Period" and the # Repeats to "3".

This specifies that the task should be scheduled 3 times a day for the duration of the planning period. Additional restrictive scheduling windows could be specified using the window definitions option at the bottom of this tab, but leave this undefined for now; we will let the deconfliction engine do the hard work for us later.

Click OK to apply the window.

Several periodic definitions could be specified for a single recurring task. You could also specify discrete windows during which the task should also be attempted.

Select the Duration tab.
Select Variable Duration and specify a Minimum Total Duration of 8 minutes.
Select the Unlimited Duration check box next to the Max Total Duration field.
Select the Resources tab.

All of the resources defined in this schedule file are listed under the Available Resources list on the left. Resources associated with an STK object have their STK object symbol next to them (such as satellite, facility, target, star, etc.).

Define the logical resource requirements formula:

Double-click on AQUA
Click AND
Double-click on OpsTeam
Click AND
Double-click on SSR
Click AND
Click on the ( ) button (parenthesis)
Double-click on Goldstone26
Click OR
Double-click on the Madrid26
Click OR
Double-click on Guam46

The Resource Constraints formula defines the resource requirements and options with a logical AND/OR statement. The AQUAcomm formula specifies that the task always requires the AQUA and OpsTeam and SSR resources, plus any one of three ground station resources (Goldstone, Guam, or Madrid). Any level of parenthesis nesting is allowed, and there is no limit on the length of the formula.

Click Create Possibilities.

The software will determine all of the individual resource string options (possibilities) that could be used to accomplish the task and will apply appropriate STK access constraints (since the Include Default STK Reports checkbox is selected) when you click Create Possibilities. As a default, constrained accesses will be required between any STK object-related resources in each resource possibility string. Accesses between ground objects in the same possibility string are not applied automatically

Select the Timeslot Definitions tab.
Select a resource possibility to view information about that resource possibility.

The three Resource Possibilities for the AQUAcomm task based on the defined Resource Constraints formula from the previous tab. The possibility priority values are calculated based on the priority of each resource in the individual possibility string.

Manually edit the task-specific priority of a possibility:

Highlight the "AQUA, Madrid26, OpsTeam, SSR" possibility option and click Edit Priority.
Enter a value of "9" and click OK

Default access reports applied to a possibility string may be edited by selecting the STK Import button.

View the effects of resource availability constraints vs. access opportunities:

Click on the Reports radio-button.
Click on another possibility string to see the STK accesses related to this option.

This view shows STK accesses for the highlighted possibility string. Other STK reports (and/or external time files) may be applied by the operator as required. Only when all reports (and file times) are satisfied (report overlaps) will report windows be created for the possibility.

Click on the Resource Availability radio-button.
Click on each of the possibility options.

This view shows the times during which all resources in the highlighted possibility string are available at the same time. Note that the one containing Madrid is missing one of the resource availability windows because the Madrid facility has a blackout period defined that covers the entire morning shift of the OpsTeam on day two of the schedule.

Click on the All Timeslots radio-button option.
Select each possibility option in turn to see the final timeslots for each.

This view shows when the resource availability and accesses overlap (these are the final timeslot options).

Click on the Timeslots Per Task radio-button option.

This view shows a listing of each final task timeslot regardless of the resources involved (resources supporting each timeslot are listed in the table).

Manually adjust timeslot scores:

Resize the column widths or scroll to the right so that the timeslot Score column is visible.

Timeslot Score is a measure of the desirability of a specific timeslot vs. other timeslots for that task, and is taken into account by the deconfliction algorithms when scoring different schedule solution options against each other. The Score of a specific timeslot is calculated based on the related possibility priority and the scheduling preference for the task (see the Task Definition window General tab). By default, the timeslot score is scaled from 0 to 100 with 100 being the highest preference, but you can change the timeslot score range in Schedule Properties.

Highlight a specific timeslot row in the Timeslot Definitions window at the bottom of the page and click Edit.
In the Timeslot Editor, change the Score value to "50" and click OK.

Note the updated timeslot score value in the timeslots window. This change makes this particular timeslot option less desirable than the others.

Change resource usage settings:

Select the Resource Usage tab.
Select the Define Per Task radio-button option.
Click on any ground station resource (Guam, Goldstone, and Madrid), then click Edit.
Set the Setup Time to 5 minutes and click OK.
Repeat the prior 2 steps for the other ground station resources.

This task-specific resource setup time will override the default resource setup time defined in its resource definition (but only for this task).

Select the SSR resource and click Edit.
Set the following properties for Capacity:

Capacity Application: Replenish
Type: Rate
Amount: 0.1 Mbytes per second

Capacity usage settings for resources with capacity can be adjusted on a per-task basis.

Click OK.

Click Update, then Close.

Six tasks (plus a recurring task Parent definition) will be added to the STK Scheduler main window Gantt view. AQUAcomm is attempted 3 times a day for a 2-day scheduling period, so the software treats it as 6 separate tasks.

De-select View > Show Task Parent Definitions to hide the Parent task definition.

The timeslots for each task are shown in the Gantt schedule area in the associated task row. Note that no scheduling has been done yet. The displayed windows are simply the times when the task could be accomplished based on resource availability, scheduling window times, and STK accesses (if applicable).

Place the mouse cursor/pointer over one of the timeslot windows in the Gantt view.

A popup form will appear that specifies the resources supporting that timeslot and the start time, stop time, duration, and resources associated with the selected timeslot.

Management Report Task

The Management Report Task is a daily report task that requires no STK resources, accesses, or reports.

Select Task > New Task.
In the Resource ID field, enter "Management Report".
Go to the Scheduling tab.
Select the Recurring Task radio-button option.
Choose Time under Scheduling Windows Defined by.
Select the Periodic Windows tab and click Add.
Set the Frequency to "Daily".
Click OK to apply the window.
Go to the Duration tab.
Select the Fixed Duration option and specify the duration as 2 hours.
Go to the Resources tab.
Double-click on "OpsTeam" from the Available Resources list.

OpsTeam should appear in the Resource Constraints formula field.

Click on the Create Possibilities button.
Click Update and Close.

Two daily management Report tasks should appear in the Gantt window with timeslots corresponding to the periods when the OpsTeam is on duty.

AQUAground Task

AQUAground is a single instance task to take a picture of a ground target with a satellite while the target is in sunlight.

Select Task > New Task.
In the Task ID field, enter "AQUAground".
Go to the Scheduling tab.
Select the Single Instance Task radio-button option.
Go to the Duration tab.
Select the Fixed Duration option and specify the duration as 1 minute.
Go to the Resources tab.
Define the logical resource requirements formula:

Double-click on AQUA
Click AND
Double-click on SSR
Click AND
Double-click on AmazonTarget

“AQUA” AND “SSR” AND “AmazonTarget” should appear in the Resource Constraints formula field.

Click on Create Possibilities.
Go to the Resource Usage tab.
Select the SSR resource and click Edit.
Set the following properties for capacity:

Capacity Application: Deplete
Type: Fixed
Amount: 75 Mbytes

Click OK.
Click Update and Close.

A single AQUAground task should be added to the Gantt window with 7 scheduling opportunities (timeslots) appearing over the entire scheduling period.

AQUAscience Task

AQUAscience is a single instance task to make an observation of a star with a satellite during satellite umbra.

Select Task > New Task.
In the Task ID field, enter "AQUAscience".
Go to the Scheduling tab.
Select the Single Instance Task radio-button option.
Select the Discrete Windows tab and click on STK Import
Click on Add.
Select the Umbra report type.
Select AQUA for STK Object 1.
Click OK, then OK again, then click OK a third time.

The umbra periods for the duration of the planning period should now be listed in the windows area at the bottom of the form. The AQUAscience task will only be scheduled once (single instance task), but it is constrained to only be scheduled during the AQUA umbra windows determined by STK.

Go to the Duration tab.
Select the Variable Duration option.
Select the Allow Multiple Segments option.
Specify the following properties for duration:

Min Total Duration: 40 minutes
Max Total Duration: 50 minutes
Min Segment Duration: 5 minutes

This duration option allows handovers between resources as well as non-contiguous task continuation as required to complete the full task duration. None of the AQUA to star access windows are 40 minutes long, but the task can be completed in segments, and this task duration option allows that.

Go to the Resources tab.
Define the logical resource requirements formula:

Double-click on AQUA
Click AND
Double-click on CassiopeiaStar_HR-21
Click AND
Double-click on SSR

“AQUA” AND “CassiopeiaStar_HR-21” AND “SSR” should appear in the Resource Constraints formula field.

Click on Create Possibilities.
Go to the Resource Usage tab.
Select the SSR resource and click Edit.
Set the following properties for capacity:

Capacity Application: Deplete
Type: Rate
Amount: 0.01 Mbyte per second

Click OK.
Click Update and Close.

A single AQUAscience task will be added to the Gantt view with repeating windows of opportunity on every orbit (constrained to umbra windows and times during which the Earth is not occulting the line of sight from the satellite to the star). Note that none of the windows are 40 or 50 minutes long. Hover the cursor over a timeslot to get the pop-up details.

AQUAattitude Task

A satellite attitude calibration task that occurs once an orbit within 30 minutes of the ascending node crossing.

Select Task > New Task.
In the Task ID field, enter "AQUAattitude".
Set the Priority to "10".

Setting the priority to 10 makes this a low-priority task.

Go to the Scheduling tab.
Select the Recurring Task radio-button option.
Choose Time under Scheduling Windows Defined by.
Verify the Apply Duration Extensions checkbox is selected.

This will allow task assignments to extend beyond the end of the timeslot boundaries to complete their duration, but still requires that they start within the timeslot boundaries.

Select the Discrete Windows tab and click on STK Import.
Click on Add.
Select the Ascending Node report type.
Select AQUA for STK Object 1.
Verify that the Window Start Time radio button and the Next Time Value In Report radio button are selected.

The Next Time Value In Report will set the duration to use the entire orbit.

Click OK and OK again.
Go to the Duration tab.
Select the Fixed Duration option.
Specify the duration as 15 minutes.

This means that every orbit (as bound by AQUA ascending node crossings), the software will attempt to schedule the start of this 15 minute task.

Go to the Resources tab.
Double-click on AQUA.

“AQUA” should appear in the Resource Constraints formula field.

Click on Create Possibilities.
Click Update and Close.

29 AQUAattitude tasks will be created (one for each orbit) and added to the Gantt window. Each task will have a single roughly 2 hour opportunity on every orbit. Scroll down through the new tasks using the scroll-bar on the right-hand side of the window.

Select File > Save to save your work before moving on to the next section where you will begin scheduling your newly created tasks.

Scheduling and Analysis

Now that you have several tasks defined it is time to solve the schedule! The next step will be to generate deconflicted schedule solutions using one or more of the deconfliction algorithms available in STK Scheduler. Expect this section to take approximately 20 minutes to complete. Actual scheduling of assignments only takes 1 or 2 seconds.

Go to Schedule > Select Algorithm and choose One-Pass.
Click on the main window toolbar.

This button is commonly referred to as the “Go” button. Clicking this button will initiate the scheduling run with the selected scheduling algorithm (which is One-Pass in this case).

Click OK when the Scheduling Status popup window indicates that the scheduling process is complete.

Once scheduling finishes, a Summary Report form will appear. The Summary Report provides an overview of the scheduling problem and the results of the scheduling run.

Click on the Summary Report Close button.
Review the Gantt window.

Scheduled tasks are shown as green bars at the time they were assigned by the scheduling algorithm. Tasks are shown in the Gantt view in time order. Unscheduled tasks are moved to the bottom of the form. This default organization can be adjusted through menu option selections under the View menu.

Adjust the Gantt view:

De-select View > Show Timeslots to toggle off the display of timeslots.

Now only the scheduled task bars are shown.

Select View > Show Timeslots to display the timeslots again.
Select View > Rollup Tasks > Rollup Recurring Tasks to roll up recurring tasks onto a single line.
De-select View > Show Task Labels to remove task labels.
Select View > Rollup Tasks > Do Not Rollup Tasks to break out each recurring task instance.

Locate a task in the Gantt:

Click on the binoculars icon on the toolbar.
Select the desired task and click OK.

The view will shift to place the selected task at the center of the Gantt window if the task is not already in the window.

Group tasks in the Gantt:

Select View > Task Groups > by STK Facility.

Tasks may be grouped on the Gantt view based on their assigned STK object type. Note that the tasks with scheduled assignments to STK facility objects have been grouped according to their assignment. Tasks without STK facility assignments are in the Ungrouped section at the bottom of the Gantt view (in time order).

Select View > Task Groups > Ungrouped to return to the normal time-ordered task view.

Calculate task conflicts:

Right-click on the AQUAattitude(1) task name or task row and select Edit Task.
Go to the Status tab and note the information shown.

The Status tab shows the start time, stop time, duration and assigned resource option for each assignment of that task.

Go to the Duration tab.
Select the Fixed Duration option.
Specify the duration as 1 hour.
Go to the Resources tab.
Click on Create Possibilities.
Click Update and Close.
Scroll down to the bottom of the Gantt view and inspect the AQUAattitude(1) task.

The task bar, which was previously red, is now uncolored, indicating the task is now unassigned.

Left-click on the task list to clear other task selections.
Right-click on AQUAattitude and select Edit Task.
Go to the Status tab.
Click on Calculate Conflicts.

Scheduler can calculate potential conflicts that may cause scheduling problem(s) for unassigned tasks, which are displayed in a Task Conflicts report. Any scheduled task using a resource utilized by the unscheduled task during any overlapping timeslot will be listed here. The AQUAattitude(02) task is listed as a potential conflict since the constraints ensure that both the AQUAattitude(01) and AQUAattitude(02) tasks cannot be scheduled simultaneously, but have overlapping timeslots. In addition to these direct conflicts, indirect conflicts due to resource setup times and consumable resource capacity are also listed. This provides conflict analysis data for unscheduled tasks.

Click Close to close the window.

Manually change task assignments:

Tasks may be manually dragged to a new time on the Gantt view. In order to drag a task it must be Locked (which indicates a manual override for scheduling purposes).

Right-click on one of the scheduled Management Report tasks and select the Lock/Override option.

The task bar will turn blue, indicating that it is Locked. The Task Lock feature is a manual override, so you can place a task anywhere (even outside task timeslots).

Click-and-drag the task bar to a new time, either during a different timeslot or during no timeslot at all.

You risk over-tasking a resource by locking and dragging a task manually. Validity checking can confirm that manual changes have not violated task or resource attributes. By default, the Validation Check will run automatically. To run a validity check manually, select Schedule > Validate.

Task validity checking is NOT performed on deferred tasks.

Locking a task and dragging it to a new timeslot may NOT change the resource assignment for the task. If multiple possibilities exist using different resources, you will be prompted to select the desired option in the Task Assignment Editor popup. The resource assignment may be manually selected on the task’s Task Definition form Status tab.

Adjust the Table view:

Select View > Main View > Table or click on the table button on the toolbar.

This will bring up the table view of the schedule.

Click on any column header to sort by the values of the data in that column.
Click on the column header again to reverse the sort.
Sort by the Status column to bring unscheduled tasks to the top.
Select View > Show Legend.

The Gantt and Table colors are viewable via this interface. The Legend form can also be used to view non-default colors assigned to resources and where these colors are displayed.

Close the Legend form.
Click-and-Drag a column header left or right to reorder the columns as desired.
Resize the columns per your preference.

Re-run the algorithms:

Right-click on a scheduled task and select the Lock/Override option.

The task status bar will turn blue and it will be brought to the top or bottom of the list if the table is still sorted by Status. A locked task (and the resources it uses) will not be changed if the schedule is re-solved. Unlocked tasks and new tasks are scheduled around locked tasks.

Go to Task > Unlock All to unlock all tasks.
Go to Schedule > Select Algorithm > Random.
Sort by the Status column to bring unscheduled tasks to the top.
Click GO

Although the One Pass algorithm assigns all tasks, the Random Algorithm may return a different result. In this instance, it cannot outperform One Pass, but in other scenarios it may. The Summary Report should tell you how it did, or you can sort by the Status column in the Table view.

View reports:

Highlight a group of tasks by selecting them with the mouse and using the SHIFT or CTRL keys

You can also select all tasks by going to Task > Select All Tasks.

Go to Task > Report.

This will generate a Task-based ASCII report for the selected tasks. All task timeslots as well as the assigned timeslot and resources are listed for each task. You can save the task report for later by clicking Save and selecting a file name and the directory location.

View the report, then click Close.
Go to Resource > Report.
Select the resource or resources you would like a report on and click OK.
View the report, then click Close.

The resource duty cycle is calculated and all supported tasks are listed under each resource.

Go to Resource > Chart > Capacity.
Select the SSR resource.
View the report, then click Close.

The SSR depletion and replenishment are shown.

Animate the schedule:

For operator/planner situational awareness, STK Scheduler also comes with a schedule animation feature.

In STK, right click on AQUA and select Zoom To.

This will set AQUA as the focus of the 3D View using the STK 3D Graphics Window.

In Scheduler, go to Schedule > STK > Animate.

The animation starts automatically once it is fully loaded.

Bring the STK 3D window to the front.
Use the 3D window controls to fast-forward the animation to just prior to the start of the AQUAcomm task.

If you turn on the Enable Timeline View for STK Animate configuration setting (located in Scheduler at File > Config > STK tab), a Timeline view of all tasks and assignments in Scheduler will be displayed in STK underneath the playing animation. To view the timeline window in STK, select View > Timeline View.

Slow down the animation to run at a reasonable speed.
Let the animation play.

This will connect AQUA with its assigned target (the facility object) during the scheduled task time. STK Scheduler can also be configured to hide displayed lines and turn on/off sensors during selected task assignments to provide even better animation of scenarios that use sensor resources.

15. Back in STK Scheduler, select View > Main View > Gantt or click on the Gantt button on the toolbar to bring up the Gantt view of the schedule.

Conclusion

This concludes the STK Scheduler tutorial. To save this schedule file select File > Save. The saved schedule file includes all of the information about all of the tasks and resources, scheduling options, timeslots, and other data necessary to bring the planning session back so you can start where you left off. Note that resources and tasks are unique to and not shared between schedule files, even though they might be associated with the same object in the same STK scenario.

Please feel free to experiment by adding to the schedule file you built here or by creating a new file from scratch. Remember that form-specific HTML Help is just a mouse click away to provide more information about any field or parameter.

If you have any questions regarding STK Scheduler, other STK modules, or this tutorial, please email STK technical support at support@agi.com or contact STK technical support by phone at 1-800-924-7244 (weekdays between 8am and 7pm, Eastern Time).