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 a little more than one hour 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

  1. Start the STK Scheduler module by double-clicking on the STK Scheduler icon on the desktop. A blank version of STK Scheduler's main Gantt view window will appear. Resize the window to make it larger, if desired.

    2. 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. Give the current blank file a name so that you can save your work and come back to it later; select File > Save As. . . . Enter the filename “STKscheduler Tutorial” and browse for the directory where you want to save it, then click Save.

  2. In order for STK objects and related access data and event reports to be applied to the scheduling problem definition (and solution), you need to associate your STK Scheduler planning file with a specific STK scenario file. Select Schedule > STK > Load Scenario. . . , click Change Scenario, and select the Tutorial.vdf scenario file from the following folder:
    3. <STK install folder>STKScheduler\STKScheduler\Scenarios\Tutorial\Tutorial.sc directory
  3. Click OK. STK Scheduler will start STK and load the selected scenario. After the STK application starts and the scenario loads, go ahead and minimize the STK application window or bring the STK Scheduler form to the front.
  4. The schedule period start and stop times are shown at the bottom of the main GUI. To set the schedule period time.:
    1. Select Schedule > Define Start/Stop. . .
    2. Set the Start Time to 2014/01/01 00:00:00 and the Stop Time to 2014/01/03 00:00:00 and click OK. This sets a two-day period for scheduling for this planning file. All recurring tasks, access calculations and other time-related information will be bounded by the start and stop times defined for the schedule file. The schedule file schedule time period is shown in the lower left corner of the main STK Scheduler form at all times.
    3. Verify that the STK Scheduler software has updated the STK scenario times to match the schedule start/stop times by right-clicking on the Tutorial scenario object in the STK Object Browser, and selecting Properties (verify start and stop times).
    4. Close the Basic Properties window and minimize the STK window.

Defining Resources

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 seven 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 20 minutes to complete.

  1. To define a new resource select Resource > New Resource. This will bring up the Resource Editor form, General tab.
  2. Type FUSE in the Resource ID field and click on Browse STK Objects to select the FUSE satellite object from the available STK scenario objects. This will associate the FUSE resource in the STK Scheduler schedule file with the FUSE satellite object in the associated STK scenario for the purposes of access calculations and event reports.

    3. Don’t worry about the other resource definition tabs for now. Default values will be assigned for Availability (always available), Accommodation (support maximum of 1 task at a time), Capacity (n/a), Notes (none), and Status (blank until scheduling is performed). You will use these tabs for other resource definitions in this section.

  3. Click Update to save the new resource and Close to close the Resource Editor form. You will see the resource listed in the resource availability section at the bottom of the Gantt view window.
  4. 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 did not change 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.
  5. When defining multiple resources associated with STK objects you can use the STK ingest tool. Select Resource > Ingest from STK and select All.
  6. Select the following STK scenario objects from the list for ingest as planning file resources and then click OK after all are highlighted (depress the keyboard CTRL key while clicking on each item with the mouse).
    7. /Scenario/Tutorial/Facility/Goldstone26
    . . . /Facility/Guam46
    . . . /Facility/Madrid26
    . . . /Star/CassiopeiaStar_HR-21
    . . . /Target/AmazonTarget

    Note that each of the new resources has been added to the FUSE 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

To Edit attributes of some of these new resources.

  1. Right-click on the Madrid26 resource and select Edit Resource from the resource popup menu to bring up the Resource Editor window with Madrid26 selected for editing.
    1. On the General tab define the "Minimum MinSetup Time" for the Madrid ground station to be 10 minutes

      2. Setup time uses the resource prior to a task’s assigned time in the schedule. However resource setup can occur prior to a task timeslot.

    2. Next select the Availability tab.

      3. Note that the Define Blackout Times – Default Available option is selected.

    3. Define a single blackout period for this resource by selecting the Discrete Windows tab and clicking on Add.
    4. Define the Window Start time to be 2014/01/02 06:00:00 and the Window Stop time to be 2014/01/02 12:00:00. Specify in the Comments field "Antenna Maintenance" and click OK. The blackout period is now listed in the Availability windows list for this resource.
    5. Click Update from this form to apply the change to the resource, then Close.
    6. In order to see the availability changes, go back to the STK Scheduler main form select View > Timescale View Properties . . . .
    7. 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.
  2. Now we will change the priority of one of the resources. Right-click on the Guam46 resource and select Edit Resource from the resource pop-up menu.
    1. On the General tab change the Priority to 8 and click Update and then Close. This will make the Guam ground station a lower priority than Goldstone or Madrid (both still set at the default priority value of 5 (middle of 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.

      2. The range and convention for task and resource priority schemes within STK Scheduler are configurable by the user under the Schedule > Properties menu, Task Priority and Resource Priority tabs.

    2. STK reports can be used to help specify the availability of a resource. We will apply a STK report to help specify the general availability of the Amazon resource. Right-click on the AmazonTarget resource at the bottom of the STK Scheduler main Gantt form view and select Edit Resource. Go to the Availability tab.
    3. 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.
    4. Select the "Sun" Report Type and "AmazonTarget" for STK Object 1. Click OK to accept the report definition and OK again to confirm that this is the only report to apply, and then confirm that the target sunlight windows for the defined two-day period are returned in the Availability windows area.
    5. These sunlight windows were retrieved from the STK software. Click Update and Close and note that 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.
  3. Another resource we are going to define is a mission operations team and it is not associated with an STK object. STK Scheduler is not limited to STK resources; any kind of resource can be defined and used as a task requirement.
    1. Select Resource > New Resource. Define the Resource ID as OpsTeam. Select the Availability tab and choose "Define Availability Times – Default Unavailable". Select the Periodic Windows tab and click on Add to bring up the Periodic Definition window and define the periodic times during which the OpsTeam will be available (when the controllers are in the control center).
    2. For Frequency select "Daily", then click Add to specify specific times during the day when the OpsTeam resource is available.
    3. Define the window start offset to be 08:00:00 and the duration to be 4 hours. Define the Window Comments to be "Morning Shift". Click OK to apply the window. Then click Add again to define another window. Specify the window start offset to be 13:00:00 with a duration of 4 hours. Define the Window Comments to be "Afternoon Shift", and click OK to apply this second window. Two windows are now defined in the Periodic definition for the OpsTeam. Window start offsets are measured from the Period Start Time for the recurring definition.
    4. These morning and afternoon shifts will be applied each day of the planning file period based on the defined Period Start Time and Period Stop Time. Click OK to apply the window.
  4. Next select the Accommodation tab and note that the default accommodation is 1 (number of simultaneous tasks that can be supported by the resource).
    1. Change the Maximum Accommodation to "2" for the OpsTeam. This indicates that the OpsTeam resource can support up to 2 tasks simultaneously. They can do two things at once. This will allow the OpsTeam to write a report and support a satellite contact at the same time, for instance.
    2. Click Update and Close, then confirm the OpsTeam resource on the main Gantt form and the expected shift times shown as aqua-colored bars (2 pairs of 4-hour periods, 1 pair for each day).
  5. The last resource we will define is an onboard solid-state-recorder (SSR). This resource will help demonstrate the use of the resource capacity attribute in task scheduling. Again select Resource > New Resource to bring up the Resource Definition form, General tab. Name the resource “SSR” by filling in the Resource ID field, and then click on the Capacity tab (we are going to leave all other attributes in their default state).
    1. Select the Is Applicable checkbox at the top of the tab. Capacity is not applicable to all resources, just those that have capacity that can be depleted or replenished (like a recorder). Define “Mbytes” in the Unit Definition field. This will help the user employ consistent units when defining tasks that use this resource capacity. Under Capacity Type select "Consumable". This means that resource capacity is permanently depleted (or replenished) by a task. The alternative, Resilient, means that resource capacity is depleted/replenished only for the duration of the task. Specify Minimum Capacity as "0", and Maximum Capacity and Initial Capacity as "100". Lastly, select Soft for resource Maximum Capacity . . . this will allow for partial replenish activities even when the resource capacity is not fully depleted.
    2. Now click Update to complete your SSR resource definition and Close out the Resource Editor window.
    3. Some resources, especially passive resources like targets, are often best defined as having Unlimited Accommodation (they never get “used up”). Edit the AmazonTarget and CassiopeiaStar_HR21 resources and note that their Accommodation is already set to Unlimited Accommodation (checkbox on Resource Accommodation tab). 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.

You have now defined eight resources for use in this planning file: 3 ground facilities (Madrid, Goldstone, and Guam), 1 satellite (FUSE), 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:

  1. A recurring satellite to ground station communications task
  2. A daily management report task that requires no STK resources, accesses, or reports
  3. A single instance task to take a picture of a ground target with a satellite while the target is in sunlight
  4. A single instance task to make an observation of a star with a satellite during satellite umbra
  5. A satellite attitude calibration task that occurs once an orbit within 30 minutes of the ascending node crossing. Expect this section to take about 30 minutes to complete.

FUSEcomm Task

  1. Select Task > NewTask . . . to define a new task and the Task Definition form (General tab) will be displayed;
  2. Enter "FUSEcomm" in the Task ID field. For this task on the General tab keep the default values; leave the Priority at the default of "5" (middle of range), keep the Scheduling Preference as "None" and Timeslot Preference as "Early", and do NOT specify any Group memberships.
  3. Select the Scheduling tab and choose Recurring Task, then choose Time for Scheduling Windows Defined by You will see a pair of tabs at the bottom of the window that allows the user to define the time-based recurring nature of the task.
  4. Select the Periodic Windows tab and click Add to define the periodic windows during which you would like this task to be scheduled.
  5. Select a Frequency to "Daily" and specify Repeat Typeto "Per Period" and # Repeats to "3". Leave the periodic start and stop times as the default (planning period start and stop). 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.

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

  6. Now that the windows during which the FUSEcomm task should be scheduled are defined, select the Duration tab to specify the duration of each instance of the task itself.
  7. Select Variable Duration and specify a Minimum Total Duration of "0 days, 00:08:00" (8 minutes). Select the Unlimited Duration check box next to the Max Total Duration field. This will maximize the duration of the task assignment within the window of a single resource set (no handovers to another ground station).
  8. Select the Resources tab to define the resource requirements and options for the task.
  9. All of the resources defined in this planning 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 (satellite, facility, target, star, etc.). To define the logical resource requirements formula for the FUSEcomm task.
    1. Double-click on the FUSE resource in the Available Resources listing
    2. Click on the AND button
    3. Double-click on the OpsTeam resource
    4. Click on the AND button
    5. Double-click on the SSR resource
    6. Click on the AND button
    7. Click on the ( ) button (parenthesis)
    8. Double-click on Goldstone26 resource
    9. Click on the OR button
    10. Double-click on the Madrid26 resource
    11. Click on the OR button
    12. Double-click on the Guam46 resource

    The Resource Constraints formula defines the resource requirements and options with a logical AND/OR statement. The FUSEcomm formula specifies that the task always requires the FUSE 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.

  10. Click Create Possibilities and 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 checkbox is selected). Select the Timeslot Definitions tab and select a resource possibility to view information about that resource possibility.
  11. Note the three Resource Possibilities for the FUSEcomm 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. To manually edit the task-specific Priority of a Possibility, highlight the "FUSE, Madrid26, OpsTeam, SSR" possibility option and click Edit Priority.
  12. Enter a value of "9" and click OK. Note the change in Priority value for the FUSE, OpsTeam, SSR, Madrid26 possibility.

    13. Note that the range and convention for Possibility priority is the same as that for Resource priority.

    Access calculations are requested from STK and applied by the STK Scheduler software during the Create Possibilities step. 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. Default access reports applied to a possibility string may be edited by selecting the STK Import button.

  13. To view the affects of resource availability constraints vs. access opportunities and how they combine to define the final “timeslots” (scheduling opportunities) for the task, click on the Reports radio-button at the bottom of the form (shows STK accesses for the highlighted possibility string). Click on another possibility string to see the STK accesses related to this option. 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.
  14. Click on the Resource Availability radio-button to display the times during which all resources in the highlighted possibility string are available at the same time. Click on each of the possibility options and 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).
  15. Then Click on the All Timeslots radio-button option to see when the resource availability and accesses overlap (these are the final timeslot options). Select each possibility option in turn to see the final timeslots for each.
  16. Next, click on the Timeslots Per Task radio-button option at the top of the tab to see a listing of each final task timeslot regardless of the resources involved (resources supporting each timeslot are listed in the table).
  17. Adjust 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), and is scaled from 0 to 100, with 100 being the highest preference.
  18. Calculated timeslot scores can be manually adjusted by the user. Highlight a specific timeslot row in the Timeslot Definitions window at the bottom of the page and click Edit to bring up the Timeslot editing window.
  19. 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.
  20. Select the Resource Usage tab and confirm the Define Per Task radio-button option.
  21. Specify a Setup time of 5 minutes for each of the ground station resources (Guam, Goldstone, and Madrid) by clicking on each resource in turn to highlight it, clicking Edit, and filling in 5 minutes (0 days, 00:05:00) under Minimum and Desired Total Setup Time
  22. Click OK each time to return to the Resource Usage tab. For Madrid, this task-specific resource setup time will override the default Madrid setup time defined in its resource definition (but only for this task).
  23. Next, select the SSR resource, click Edit, and specify that the FUSEcomm task Replenishes the SSR resource at a Rate of 0.1 Mbytes per second and click OK.
  24. Click Update to apply the task definition and then Close to close the Task Editor window. Six tasks (plus a recurring task Parent definition) will be added to the STK Scheduler main window Gantt view.

    25. FUSEcomm is attempted 3 times a day for a 2-day scheduling period, so the software treats it as 6 separate tasks

  25. De-select View > Show Task Parent Definitions to hide the Parent task definition.
  26. 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).
  27. Place the mouse cursor/pointer over one of the timeslot windows in the Gantt view and 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

  1. Select Task > New Task. On the General tab of the Task Definition form specify the Task ID as "Management Report". Leave all else on the General tab as default values.
  2. Select the Duration tab and select the Fixed Duration option. Specify the duration as 2 hours at the bottom of the form (0 days 02:00:00).
  3. Select the Resources tab and double-click on "OpsTeam" from the Available Resources list (OpsTeam should appear in the Resource Constraints formula field). Click on the Create Possibilities button and then click Update and Close.
  4. Two daily management Report tasks should appear in the Gantt window with timeslots corresponding to the periods when the OpsTeam is on duty.

FUSEground Task

  1. Select Task > New Task. On the General tab of the Task Definition form specify the Task ID as "FUSEground". Leave the General tab as default values.
  2. Select the Scheduling tab and select the Single Instance Task radio-button option.
  3. Select the Duration tab and select the Fixed Duration option. Specify the duration as 1 minute on the form (0 days 00:01:00.000).
  4. Select the Resources tab and double-click on the FUSE resource from the Available Resources list, then click AND, double-click on the SSR resource, click AND, and finally double-click the AmazonTarget resource from the Available Resources list. “FUSE” AND “SSR” AND “AmazonTarget” should appear in the Resource Constraints formula field. Click on Create Possibilities.
  5. Select the Resource Usage tab and then select the SSR resource and Edit. Specify that the FUSEground task Deplete the SSR Capacity by a Fixed amount of 75 Mbytes .
  6. Click Update and Close to apply the task definition. A single FUSEground task should be added to the Gantt window with 6 or 7 scheduling opportunities (timeslots) appearing on each day.

FUSEscience Task

  1. Select Task > New Task. On the General tab of the Task Definition window specify the Task ID as "FUSEscience". Leave everything on the General tab as default values.
  2. Select the Scheduling tab and select the Single InstanceTask radio-button option. Select the Discrete Windows tab and click on STK Import, then on Add. Select the Umbra report type and FUSE for STK Object 1. Leave everything else as the default value and click OK, then OK again. The umbra periods for the duration of the planning period should now be listed in the windows area at the bottom of the form.
  3. The FUSEscience task will only be scheduled once (single instance task), but it is constrained to only be scheduled during the FUSE umbra windows determined by STK.
  4. Select the Duration tab and select the Variable Duration option. Then select the Allow Multiple Segments option. Specify the Min Segment Duration as 5 minutes (0 days 00:05:00.000), the Max Total Duration as 50 minutes (0 days 00:50:00.000) and the Min Total Duration as 40 minutes (0 days 00:40:00.000). 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 FUSE to star access windows are 40 minutes long, but the task can be completed in segments, and this task duration option allows that.
  5. Select the Resources tab and double-click on the FUSE resource from the Available Resources list. Then click AND and double-click the CassiopeiaStar_HR-21 resource from the Available Resources list. Then click AND and double-click the SSR resource from the Available Resources list “FUSE” AND “CassiopeiaStar_HR-21” AND “SSR” should appear in the Resource Constraints formula field. Click on Create Possibilities then select the Resource Usage tab and Edit the SSR resource to Deplete at a Rate of 0.01Mbytes/second and click OK. Select Update to add this new task to the system and then Close the Task Editor window.
  6. A single FUSEscience 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).

FUSEattitude Task

  1. Select Task > New Task. On the General tab of the Task Definition form specify the TaskID as "FUSEattitude". Define the Priority as "10" (making this a low-priority task). Leave all else on the General tab as default values.
  2. Select the Scheduling tab and select the Recurring Task radio-button option and select the Time radio button for the recurring basis. Verify 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 and Add.
  3. Select the Ascending Node report type, FUSE for STK Object 1, and verify that the Window Start Time radio button is selected, and the Next Time Value In Report radio button is selected. Click OK and OK again. The Next Time Value In Report will set the duration to use the entire orbit.
  4. Select the Duration tab and select the Fixed Duration option. Specify the duration as 15 minutes (0 days 00:15:00.000). This means that every orbit (as bound by FUSE ascending node crossings), the software will attempt to schedule the start of this 15 minute task.
  5. Select the Resources tab and double-click on the FUSE resource from the Available Resources list. “FUSE” should appear in the Resource Constraints formula field. Click on Create Possibilities.
  6. Click Update to apply the task and Close to close the Task Editor window.
  7. FUSEattitude tasks will be created (~28 . . . one for each orbit) and added to the Gantt window with a single ~ 2 hour opportunity on every orbit. Scroll down through the new tasks using the scrollbar on the right-hand side of the window.
  8. Select File > Save to save your work before moving on to the next section where you will get down to doing some scheduling.

Scheduling and Analysis

  1. 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 5 minutes to complete. Actual scheduling of assignments only takes 1 or 2 seconds.
  2. Select Schedule > Select Algorithm and choose One-Pass.
  3. Click (commonly referred to as the “Go” button) on the main window toolbar to initiate the scheduling run using the One-Pass scheduling algorithm. Click OK when the Scheduling Status popup window indicates that the scheduling process is complete. A Summary Report form will provide an overview of the scheduling problem and the results of the scheduling run.
  4. Click on the Summary Report Close button and review the Gantt form. Note that scheduled tasks are shown as green bars at the time they were assigned by the scheduling algorithm.
  5. 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 by the user through menu option selections under the View menu.
  6. Select View > Show Timeslots to toggle off the display of timeslots; now only the scheduled task bars are shown. Turn the timeslots back on by selecting View > Show Timeslots again.
  7. Roll up recurring tasks onto a single line by selecting View > Rollup Tasks > Rollup Recurring Tasks. Remove task labels by de-selecting View > Show Task Labels.
  8. Break out each recurring task instance by again selecting View > Rollup Tasks > Do Not Rollup Tasks.
  9. To quickly find a single task in a long task list, 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.
  10. Tasks may be grouped on the Gantt view based on their assigned STK object type. Select View > Task Groups > by STK Facility.
  11. 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.
  12. Right-click on the FUSEattitude(27) task name or task row to bring up a menu of task options, select Edit Task... to bring up the Task Editor window. Select the Status Tab and note the information on start time, stop time, duration, and assigned resource option.
  13. Select the Duration tab and select the Fixed Duration option. Specify the duration as 1 hour at the bottom of the form (0 days 01:00:00). Select the Resources tab and click on Create Possibilities. Click Update to apply the task and Close to close the Task Editor window.
  14. Scroll down to the bottom of the Gantt view and inspect the FUSEattitude(28) task . The task is now unassigned. Left click (to clear other task selections) then right-click on the FUSEattitude(27) task. Select Edit Task... to bring up Task Editor. Select the Status tab. Click on Calculate Conflicts to display specific conflicts that caused the scheduling problem(s) for the task.
  15. Any scheduled task using a resource option for the unscheduled task during any timeslot for the unscheduled task will be listed here. The FUSEattitude(28) task is listed as a conflict since the constraints create a situation where both the FUSEattitude(28) and FUSEattitude(28) tasks cannot be scheduled simultaneously. 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.
  16. De-select View > Show Unassigned Tasks to remove unassigned tasks from the Gantt window.
  17. 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. Next, click-and-drag the task bar to a new time (perhaps during a different timeslot or maybe during no timeslot at all). Validation Check will automatically run. To run a validity check manually select Schedule > Validate

    18. The user risks over-subscribing a resource by locking and dragging a task manually. Validity checking can confirm that manual changes have not violated task or resource attributes.

    The Task Lock feature is a manual override so the user can place a task anywhere (even outside task timeslots). Task validity checking is NOT performed on locked or deferred tasks, though related resource impacts are checked for locked tasks

    Note that 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, the user will be prompted to select the desired option. The resource assignment may be manually selected on the task’s Task Definition form Status tab.

  18. Select View > Main View > Table or click on the table button on the toolbar to bring up the table view of the schedule.
  19. Click on column headers 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; this is a quick way to consolidate the unscheduled tasks on the table view.
  20. Select View > Show Legend to help decipher the symbols used for the different status levels and task object type definitions.
  21. 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. On the table view, Click-and-Drag a column header left or right to reorder the columns as desired, and resize the columns per your preference.
  22. Left-click on a scheduled task to select it, then right-click and select the Lock/Override option from the pop-up menu. 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.
  23. Unlock all tasks (use the Task > Unlock All menu option) and Select Schedule > Select Algorithm > Random and then hit GO to resolve the schedule. 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.
  24. Highlight a group of tasks in the table view by selecting them with the mouse and using the SHIFT or CTRL keys. To select all use the Task > Select All Tasks menu option. To get a Task-based ASCII report for the selected tasks, select Task > Report.
  25. All task timeslots as well as the assigned timeslot and resources are listed for each task. Save the task report for later use by clicking Save and selecting a filename and the directory location.
  26. To get a Resource-based report select Resource > Report. With the mouse select the resource or resources you would like a report on and click OK.
  27. Review the Resource report on the screen. Note that resource duty cycle is calculated and all supported tasks are listed under each resource.
  28. To assess resource capacity usage select Resource > Chart > Capacity.
  29. Zoom in on the main Gantt View first to see a closer view of the chart (the main Gantt View zoom setting is used to drive the chart zoom level). The SSR depletion and replenishments are shown.
  30. For operator/planner situational awareness, STK Scheduler also comes with a schedule animation feature. To help focus in on this schedule’s animation, In STK, right click on FUSE and select Zoom To.., this will set FUSEas the focus of the 3D View using the STK 3D Graphics Toolbar.
  31. Look at the Gantt view of STK Scheduler to find the start time of the FUSEcomm task. Select Schedule > STK > Animate, bring the STK 3D window to the front (animation starts automatically), and use the 3D window controls to fast-forward the animation to just prior to the start of the task, and then slow it down to run at a reasonable speed.
  32. This will connect FUSE 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.
  33. Select View > Main View > Gantt or click on the table 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).

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