Duration Tab

The duration tab contains the controls that allows you to define the length of time that a task requires.

To display the Duration Tab, select Task -> New or Task -> Edit from the Menu Bar, then click on the Duration Tab.

Duration Tab

Only Timeslots that are equal to or larger than the minimum task duration will be created. Therefore if editing an existing task, the Create Possibilities button on the Resources Required Tab must be clicked if task's duration is changed.

Fixed Duration Option Button

The fixed duration option button allows you to define the exact amount of time a task requires. STK Scheduler will assign the task only if it is the defined exact fixed duration can be accommodated. Clicking the fixed duration button makes the Fixed Duration Definition frame visible.

Fixed Duration Textbox

The fixed duration textbox allows you to define the days, hours, minutes, and seconds required to complete a task. With this option selected, a task may receive only one assignment. STK Scheduler will only accept positive integer numbers. Alternatively, the and buttons may be used to select a duration. The fixed duration textbox is only visible when the Fixed Duration Option Button is selected (not shown above).

Variable Duration Option Button

The variable duration option button allows you to define a task that may vary in duration. The variations include options if the full timeslot is required, minimum and maximum durations required, or multi-segments and handovers are required. Selecting the Variable Duration option causes the Variable Duration Properties Frame to appear.

Full Timeslot Required Checkbox

The Full Timeslot Required checkbox allows you to define a task that requires a full entire timeslot to be assigned (all or none). With this option selected, a task may receive only one assignment. This option is only available when the Variable Duration Option is selected.

Minimum Total Duration Textbox

The Minimum Total Duration Textbox allows you to define the minimum length of time that is required to be assigned to the task's duration. This includes the Minimum Segment Duration (minimum single assignment duration) for tasks that allow Handovers. STK Scheduler will only accept positive integer numbers, and the minimum duration may not be defined as less than one second. Alternatively, the and buttons may be used to select a duration. The Minimum Total Duration textbox becomes available when the Variable Duration option is selected and is not active when the Require Full Timeslot option is selected.

Maximum Total Duration Textbox

The Maximum Total Duration Textbox allows you to define the maximum length of assigned time that cannot be exceeded for the task's duration. STK Scheduler will only accept positive integer numbers. Alternatively, the and buttons may be used to select a duration. The Maximum Duration Textbox becomes available when the Variable Duration option is selected and is not active when the Require Full Timeslot option is selected.

When handovers, or "multiple segments", are permitted, the maximum total duration applies to the total aggregate assigned duration of all timeslot assignments, excluding overlaps.

Unlimited Duration Checkbox

The Unlimited Duration Checkbox allows you to leave the maximum length of time that may be assigned to the task's duration as unbounded. With this option checked the maximum duration is limited only by the duration of the timeslots to which it may be assigned. When this checkbox is not checked, the Maximum Total Duration Textbox becomes active.

Allow Multiple Segments Option Checkbox

The Allow Multiple Segments Option Checkbox allows you to specify that the duration of the task will be maximized by allows in handovers to occur between the task's various timeslots. The task is therefore capable of receiving multiple assignments. STK Scheduler will allow temporal breaks between successive timeslot assignments and also allow transitions from on possibility (resource set) to another. STK Scheduler will attempt to give assignments to the task for the entire scheduling period or until the total aggregate assigned duration, excluding overlaps, is equal to the maximum total duration (if not unlimited). Selecting the Allow Multiple Segments Option Checkbox causes the Minimum Segment Duration Textbox and Allow Resource Changes Between Segments Checkbox to become active.

Minimum Segment Duration Textbox

The Minimum Segment Duration Textbox allows you to define the minimum length of time that may be assigned to task's segment duration. STK Scheduler will only accept positive integer numbers. Alternatively, the and buttons may be used to select a duration.

The Minimum Segment Duration Textbox becomes available when the Allow Multiple Segments Option Checkbox is selected.

Allow Resource Changes Between Segments Checkbox

The Allow Resource Changes Between Segments checkbox allows you to specify that different resources can be used to satisfy multiple segments of a task assignment. The Allow Resource Changes Between Segments Checkbox becomes available when the Allow Multiple Segments Option Checkbox is selected. Checking this box makes the Allow Gaps Option Button, Require Overlap Option Button, and Resource Overlap Duration Textbox to become active.

Allow Gaps Option Button

The Allow Gaps Option Button allows you to specify that temporal gaps may separate multiple segments of a task assignment. This option will cause the scheduling algorithms to prefer overlap, with the maximum overlap allowed set with the Maximum Overlap setting. The Allow Gaps Option becomes available when the Allow Resource Changes Between Segments Option Checkbox is selected. Selecting this option makes the Require Overlap Option Button and Resource Overlap Duration Textbox to become inactive.

Maximum Overlap

The Maximum Overlap setting allows you to specify the maximum amount of overlap allowed for assignments generated by the scheduling algorithms. If no maximum overlap is provided the algorithms will not create any assignments that overlap. The Maximum Overlap setting becomes available when the Allow Gaps radio button is selected.

Require Overlap Option Button

The require Overlap Option Button allows you to specify that temporal gaps may not separate multiple segments of a task assignment. The Allow Gaps Option becomes available when the Allow Resource Changes Between Segments Option Checkbox is selected. Selecting this option makes the Require Overlap Option Button and Resource Overlap Duration Textbox to become inactive.

Resource Overlap Duration Textbox

The Resource Overlap Duration Textbox allows you to specify the duration, if any, that is required for multiple segments of a task assignment. The Resource Overlap Duration Textbox becomes available when the Require Overlap Option Button is selected. STK Scheduler will only accept positive integer numbers. Alternatively, the and buttons may be used to select a duration. A zero value specifies that sequential assignments are adjoining, without overlaps or gaps.

Note: Enforcing a Gap Between Handover Assignments

A gap can be enforce between assignments by applying a virtual resource to the resource formula (where the virtual resource is used in every possibility). Set the virtual resource with a minimum setup time to the desired minimum gap duration.

Start No Later Than Constraints

The Start No Later Than Constraints Frame displays any constraints related to the selected task that specify task assignments cannot occur later than another event within the schedule.