### Note

Extracted from Epic <mention class="mention" data-id="31992" data-type="work_package" data-text="#31992">#31992</mention> related to duration.

This work package describes how values for the start date, the finish date and duration should change in response to changes to any of one of them.

A lot of these are self-explanatory, but explicitly describing these behaviours helps us particularly in the testing phase to ensure that the date picker behaves as logically and intuitively as possible, whilst also reducing chances of data loss (for example, accidentally having a start date change when the user does not expect it).

### Scenarios

#### Scenario 1

* Setup.
* Start date: Monday, February 8, 2021
* Finish date: empty
* Duration: empty
* Change
* User enters a duration of 10 days (duration in focus)
* Expected result:
* The finish date is set Friday, February 19 2021 (derived)

#### Scenario 2

* Setup
* Start date: empty
* Finish date: empty
* Duration: empty
* Change
* User enters a duration of 10 days
* Expected result:
* No date is added

#### Scenario 3

* Setup
* Start date: empty
* Finish date: Friday, February 19, 2021
* Duration: empty
* Change
* User enters a duration of 10 days (duration in focus).
* Expected result:
* The start date is set to Monday, February 8, 2021 (derived)

#### Scenario 4

* Setup
* Start date: Monday, February 8, 2021
* Finish date: Friday, February 19, 2021
* Duration: 10
* Change
* User changes duration to 11 days (duration in focus).
* Expected result:
* The finish date is changed to Monday, February, 22 2021

#### Scenario 5

* Setup
* Start date: Monday, February 8, 2021
* Finish date: Monday, February 22, 2021
* Duration: 11
* Change
* User changes duration to 10 days (duration in focus)
* Expected result:
* The finish date is changed to Friday, February, 19, 2021
* unless NWD are included, in which case, finish date is changed to Sunday, February, 21, 2021.

#### Scenario 6

* Setup
* Start date: Tuesday, February 9, 2021
* Finish date: Friday, February 12, 2021
* Change
* Remove duration.
* Expected result
* Finish date is also removed, start date is maintained as is.

#### Scenario 7

* Setup
* Start date: Monday, February 8, 2021
* Finish date: Wednesday, February 11, 2021
* Duration: 4
* Change
* User alters the start date to Tuesday, February 9, 2021 (start date in focus)
* Expected result
* Finish date is maintained, duration is automatically adjusted to 3 days (derived; logic = changing one date when the other is present affects duration vs. move the second date).

#### Scenario 8

* Setup
* Start date: Tuesday, February 9, 2021
* Finish date: Friday, February 12, 2021
* Duration: 4
* Change
* User alters the finish date to Feb 11, 2021 (finish date is in focus).
* Expected result
* Start date is unaffected, duration is now set to 3 days (derived from dates)

#### Scenario 9

* Setup
* Start date: empty
* Finish date: empty
* Duration: 4
* Change
* User enters the finish date of Friday, February 12, 2021 (finish date in focus).
* Expected result
* The start date is set to Tuesday, February 9, 2021 (derived from duration).

#### Scenario 10

* Setup
* Start date: empty
* Finish date: Thursday, February 11, 2021
* Duration: empty
* Change
* User enters the start date of Tuesday, February 09, 2021 (start date in focus).
* Expected result
* Duration is set to 3 (derived from start date)

#### Scenario 11

* Setup
* Start date: Monday, February 9, 2021
* Finish date: Wednesday, February 11, 2021
* Duration: 3
* Change
* The user moves the drag handle on the left border (start date) of the box representing the work package in Gantt chart and Team planner one day to the right (to Feb 10, 2021)
* Expected result
* The duration is reduced to 2. The start date is set to Feb 10, 2021. The finish date is left unchanged.

#### Scenario 12 Begin of the insertion(GANTT/Team planner)End of the insertion

* Setup
* Start date: Tuesday, February 9, 2021
* Finish date: Thursday February 11, 2021
* Duration: 3
* Change
* The user moves the work package by dragging it Begin of the insertion(on the GANTT/team planner) itEnd of the insertion to the Begin of the insertion**right**End of the insertion Begin of the deletion rightEnd of the deletion so start date is Begin of the insertionWednesday, February 10,End of the insertion Begin of the deletion Friday,  Feb 12,End of the deletion 2021.
* Expected result
* The duration is maintained. Start state is now Begin of the insertionWednesday,End of the insertion Begin of the deletion Friday,End of the deletion Febuary Begin of the insertion10 (as set by drag), end date is set Friday, FebruaryEnd of the insertion 12 Begin of the insertion(derived based on duration).

#### Scenario 12bis (GANTT/Team planner)

* Setup
* Start date: Tuesday, February 9,End of the insertion 2021 Begin of the insertion
* Finish date: Thursday February 11, 2021
* Duration: 3
* Change
* The user moves the work package by dragging it (on the GANTT/team planner) it to the **left** so start date is Monday, Febuary 8, 2021.
* Expected result
* The duration is maintained. Start state is now Monday, February 8, 2021End of the insertion (as set by drag), end date is set Begin of the insertionto Wednesday,End of the insertion Begin of the deletion Tuesday, Friday,End of the deletion February Begin of the insertion11End of the insertion Begin of the deletion 16End of the deletion (derived based on duration).

#### Scenario 13

* Setup
* Start date: Tuesday, February 9, 2021
* Finish date: Thursday, February 11, 2021
* Duration: 3
* Change
* The user Begin of the insertionchangesEnd of the insertion Begin of the deletion movesEnd of the deletion the start day Begin of the insertionon the datepickerEnd of the insertion to Wednesday, Begin of the insertionMarch 3,End of the insertion Begin of the deletion **March 3**,End of the deletion 2021 (note that this is _after_ the original start date).
* Expected result
* Begin of the insertionSinceEnd of the insertion Begin of the deletion Duration is maintained andEnd of the deletion the Begin of the insertionnew startEnd of the insertion Begin of the deletion finishEnd of the deletion date is Begin of the insertion_after_ the old finish date, both the start and finish dates are changedEnd of the insertion Begin of the deletion now movedEnd of the deletion to Begin of the insertionWednesday,End of the insertion Begin of the deletion Friday,End of the deletion March Begin of the insertion3. Duration is now 1.End of the insertion Begin of the deletion 5, 2021.End of the deletion

#### Scenario 14

* Setup
* Start date: Tuesday, February 9, 2021
* Finish date: Thursday, February 11, 2021
* Duration: 3
* Change
* The user Begin of the insertionchangesEnd of the insertion Begin of the deletion movesEnd of the deletion the start day Begin of the insertionon the datepickerEnd of the insertion to Wednesday, Begin of the insertionFebruary 3,End of the insertion Begin of the deletion **February 3**,End of the deletion 2021 (note that this is _before_ the original start date).
* Expected result
* The start date is now Wednesday, February 3.
* The finish date is conserved (Thursday, February 11, 2021).
* The duration is updated to 7 days.

### Archived Scenarios

The following scenarios are no longer relevant because they deal with behaviour concerning follows/preceeds and parent/child relationship that do not change with the introduction of duration. They are nevertheless retained here as an archive.

#### ~~Scenario 15~~

* ~~Setup~~
* ~~Two work packages~~
* ~~Task 1:~~
* ~~Start date: Monday, 15 February, 2021~~
* ~~End date: Wednesday, 17 February, 2021~~
* ~~Duration: 3~~
* ~~Task 2:~~
* ~~Start date: empty~~
* ~~End date: empty~~
* ~~Duration: empty.~~
* ~~Change~~
* ~~Change relations such that Task 2 preceeds Task 1.~~
* ~~Expected result~~
* ~~Dates for Task 2 are derived from this &quot;proceeds&quot; relation.~~
* ~~Start date: Friday, 12 February, 2021 (dates including and after the work package this one preceedes are blocked)~~
* ~~Duration: 1 (automatic)~~
* ~~End date: Friday, 12 February, 2021 (derived from duration)~~
* ~~Warning: Reminder the start and end dates need to be before the dates of the work package this one is preceeding.~~
* ~~**\[open\]** Invalid dates are disabled.~~ _~~This is something that needs to be explored further, both in terms of development effort and the impact on usability and comprehension.~~_
* ~~**\[open\]** Possible challenge: what if the dates are limited by another work package that the user (who can modify the dates for the current work package) cannot see, because of permissions?~~

#### ~~Scenario 16~~

* ~~Setup~~
* ~~Two work packages~~
* ~~Task 1:~~
* ~~Start date: Monday, 15 February, 2021~~
* ~~End date: Wednesday, 17 February, 2021~~
* ~~Duration: 3~~
* ~~Task 2:~~
* ~~Start date: Thursday, 11 Febuary, 2021~~
* ~~End date: Monday, 17 February, 2021~~
* ~~Duration: 5~~
* ~~Change~~
* ~~Change relations such that Task 2 preceeds Task 1.~~
* ~~**\[open, to be discussed\]** Expected result~~
* ~~Dates for Task 2 are changed, such that finish date is the first available date preceeding Task 1. Duration is conserved:~~
* ~~Start date: Monday, 8 February, 2021 (derived from duration and finish date)~~
* ~~Duration: 5~~
* ~~End date: Friday, 12 February, 2021~~
* ~~Warning: Reminder the start and end dates need to be before the dates of the work package this one is preceeding.~~

~~**\[note\]** Today, the behaviour today seems inconsistent.~~

~~For example, in this example,~~ _~~Test a3~~_ ~~begins after~~ _~~Test a2~~_~~. When~~ _~~Test a3~~_ ~~is given a &quot;preceeds&quot; relationship at~~ _~~a2~~_~~, dates don&#39;t automatically adjust:~~

<figure class="image op-uc-figure" style="width:75%;"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/31006/content"></div></figure>

~~If we flip the relationship, (give Test~~ _~~a2~~_ ~~a &quot;preceeds&quot; relationship to~~ _~~Test a3),~~_ ~~the dates for Test a3 seem to adjust automatically so it follows a2:~~

<figure class="image op-uc-figure" style="width:75%;"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/31007/content"></div></figure>

~~This second behaviour seems reasonable; a2 terminates on 22.10, so a3 automatically starts on 23.10. Do we want to preseve this? Or perhaps make the behaviour more consistent between the two cases?~~

#### ~~Scenario 17~~

* ~~Setup~~
* ~~Two work packages~~
* ~~Task 1:~~
* ~~Start date: Monday, 8 February, 2021~~
* ~~End date: Wednesday, 10 February, 2021~~
* ~~Duration: 3~~
* ~~Task 2:~~
* ~~Start date: empty~~
* ~~End date: empty~~
* ~~Duration: empty~~
* ~~Change~~
* ~~Change relations such that Task 2 follows Task 1.~~
* ~~Expected result~~
* ~~Dates for Task 2 are derived from this &quot;follows&quot; relation.~~
* ~~Start date: Thursday, 11 February, 2021~~
* ~~Duration: 1 (automatic)~~
* ~~End date: Thursday, 11 February, 2021 (derived from duration)~~
* ~~Warning: Reminder the start and end dates need to be after the work package this one following.~~
* ~~**\[open\]** Invalid dates are disabled.~~ _~~This is something that needs to be explored further, both in terms of development effort and the impact on usability and comprehension.~~_
* ~~**\[open\]** Possible challenge: what if the dates are limited by another work package that the user (who can modify the dates for the current work package) cannot see, because of permissions?~~

#### ~~Scenario 18~~

* ~~Setup~~
* ~~Two work packages~~
* ~~Task 1:~~
* ~~Start date: Monday, 15 February, 2021~~
* ~~End date: Friday, 19 February, 2021~~
* ~~Duration: 5~~
* ~~Task 2:~~
* ~~Start date: Tuesday, 16 Febuary, 2021~~
* ~~End date: Thursday, 18 February, 2021~~
* ~~Duration: 3~~
* ~~Change~~
* ~~Change relations such that Task 2 follows Task 1.~~
* ~~**\[open, to be discussed\]** Expected result~~
* ~~Dates for Task 2 are changed, such that finish date is the first available date following Task 1. Duration is conserved:~~
* ~~Start date: Monday, 22 February, 2021~~
* ~~Duration: 3~~
* ~~End date: Wednesday, 14 February, 2021~~
* ~~Warning: Reminder the start and end dates need to be after the dates of the work package this one is following.~~

~~**\[note\]** Today, the behaviour today seems inconsistent.~~

~~For example, in this example,~~ _~~Test a3~~_ ~~begins after~~ _~~Test a2,~~_ ~~but before its finish date. When~~ _~~Test a2~~_ ~~is given a &quot;follows&quot; relationship at~~ _~~a3~~_~~, dates don&#39;t automatically adjust:~~

<figure class="image op-uc-figure" style="width:75%;"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/31009/content"></div></figure>

~~If we flip the relationship, (give Test~~ _~~a2~~_ ~~a &quot;follows&quot; relationship to~~ _~~Test a3),~~_ ~~the dates for Test a3 seem to adjust automatically so it follows a2:~~

<figure class="image op-uc-figure" style="width:75%;"><div class="op-uc-figure--content"><img class="op-uc-image" src="/api/v3/attachments/31008/content"></div></figure>

~~This second behaviour seems reasonable; a2 terminates on 22.10, so a3 automatically follows on the next available day, 23.10. Do we want to this? Or perhaps make the behaviour more consistent between the two cases?~~

#### ~~Scenario 19~~

* ~~Setup~~
* ~~Two work packages~~
* ~~Task 1:~~
* ~~Start date: Monday, 8 February, 2021~~
* ~~End date: Wednesday, 10 February, 2021~~
* ~~Duration: 3~~
* ~~Task 2:~~
* ~~Start date: empty~~
* ~~End date: empty~~
* ~~Duration: empty.~~
* ~~Change~~
* ~~Change relations such that Task 2 is a child of Task 1.~~
* ~~Expected result~~
* ~~Since the parent does not have any date information, dates and duration for Task 1 are derived from the child (as shown below)~~
* ~~The work package is automatically scheduled.~~
* ~~Start date: Monday, 8 February, 2021~~
* ~~End date: Wednesday, 10 February, 2021~~
* ~~Duration: 10~~