Put the activities (tasks) in their natural order by defining their predecessor-successor relationships (links). This way, moving a task will change the successors position accordingly.
To create links, move the mouse over the predecessor bar in Gantt Chart until the cursor appear and drag to the successor bar or select the tasks and click the icon (it chains selected tasks by links and works for multiple task selection, too).
The default link type is Finish-to-Start.
Double-click the link arrow in the chart to open Dependency details window. Now you can set the link's lag, that means the delay between the specified dates of the predecessor and successor (e.g. for Finish-to-Start, lag time is the delay between the predecessor's Finish, and the successor's Start). A negative lag is equivalent with a positive lead time.
To delete a link double click on it and press Delete button in Dependency details window, or select tasks (it can be a multiple selection) and click the icon (all links between selected tasks will be deleted).
A constraint to a task can be set by selecting its type and date in the Details tab in Details window.
The applicable constraints are:
As Soon As Possible (ASAP) - the task will start at the project estimated start date (no constraint will be set)
Start No Earlier Than (SNET) - the task will start at the selected date or later (if it is "pushed" by links)
Start No Later Than (SNLT) - the task can't start later than the selected date, even if a link is forcing this (in this situation an error message may appear and the command will not be executed)
Finish No Earlier Than (FNET) - the task will end at the selected date or later
Finish No Later Than (FNLT) - the task can't end later than the selected date, even if a link is forcing this (in this situation an error message may appear and the command will not be executed)
Must Start On (MSO) - the task will start exactly at the selected date
Must Finish On (MFO) - the task will end exactly at the selected date
Attention: Moving a task bar in the Gantt graph by dragging it with the mouse cursor will set a Start No Earlier Than (SNET) constraint on the task!
Besides constraints, a deadline date can be associated to each task. If task end date becomes later than deadline date, a warning sign will appear in Info column.
Estimate each activity duration and set it in the duration column.
Some tasks could require different calendars from the project's one (e.g.: an activity that cannot be interrupted should have a 24-hours calendar, but the others follow a standard 8-hours calendar). Assign calendars to tasks by clicking in the corresponding cell from Calendar column and selecting the right one. If it's necessary, define additional calendars at the Calendar step in the Guide with the New command, or in the Settings menu, Calendar (see Define calendars section).
Resources use task calendar checkbox in the Details tab will force the assigned resources to work following the task working program. By marking this option the resources will work at the current task following task calendar instead of its own calendar. This makes possible to bring a resource to work even for its non-working hours (but working hours for task). Consequently, the resource will accumulate overtime hours (that can be paid with a different hourly rate than regular working hours - see Insert human and equipment resources section).
The checkboxes Always keep assignment units as set (fix-units task) and Try to keep the work when changing resources/duration (make task work-driven) will determine task behavior when changing the assigned resources or one of the three variables (work, duration, units). For example, when adding a resource, if the first one is checked the work will be modified (units will be kept), but if both are checked the duration will be accommodated (units and work will be kept).
Hint: the above mentioned checkboxes can be also found in the Resources tab.
Edit notes to remember important details related to tasks.
Hint: you may personalize Gantt table by adding or deleting columns, including custom ones. Right click on the header and insert new columns or click on the button in the upper-right corner of the table and mark only the columns you need (see more in Tables settings section) .