Link activities
===============

.. index:: Link activities

Activities can be linked with each other in Gantt chart, network
charts and Gantt-network charts.

The following link types are at your disposal:

+-----------------------------------+--------------------------------------------------------------------------------------------+
| **Finish-Start**                  | the "from" activity must finish before the "to" activity can start                         |
+-----------------------------------+--------------------------------------------------------------------------------------------+
| **Start-Start**                   | the "from" activity must start before the "to" activity can start                          |
+-----------------------------------+--------------------------------------------------------------------------------------------+
| **Finish-Finish**                 | the "from" activity must finish before the "to" activity can finish                        |
+-----------------------------------+--------------------------------------------------------------------------------------------+
| **Start-Finish**                  | the "from" activity must start before the "to" activity can finish                         |
+-----------------------------------+--------------------------------------------------------------------------------------------+
| **Incompatible activity group**   | Activities that must not be executed at the same time (time conflicts)                     |
+-----------------------------------+--------------------------------------------------------------------------------------------+

You can unhide the Properties window of any link by doubleclicking on the link.

|image0|

**Time intervals**

Intervals can be defined in Project properties in relation to the time
unit of the duration (such as hours or days).
You can choose among the following types of intervals:

- in absolute time (1 day consists of 24 hours, that is, for example, 8 hours and 16 non-working hours)
- in calendar time (depending on the actual calendar, for example, 1 day consists of 8 hours, that is, it
  ignores non-working hours)
- in relative time (for instance, a particular percentage, relating to
  the "to" activity, such as: 50%)

**Intervals can have**

- positive (such as: + 2 hours) or
- negative (such as: - 50% = overlapping)

signs.

**Highlight link**

Links can be highlighted by means of colour or boldface.

**Create link**

In order to create a new link, do as follows:

- Choose the link type via the menu **Start > Insert > Link**.

|image1|

- Connect two activities by drawing your mouse from one activity to
  another.
- Choose the interval type for the link in the Properties window.
- If necessary, enter the Delay (positive or negative) by which you want
  to delay the "to" activity depending on the selected type of link. 
- Click on the button **OK**.

**Alternatively:** You can create link activities in the diagrams via the
context menu.

|image2|

|image3|

**Notes (restrictions in the links creation):**

-  The occurrence of an activity is only allowed in incompatible
   activity groups.

.. |image0| image:: ../images/link_property_general.png
.. |image1| image:: ../images/link_property_menu.png
.. |image2| image:: ../images/link_property_create_1.png
.. |image3| image:: ../images/link_property_create_2.png