In this article:

Highlight and filter critical tasks and longest path
Critical task calculation
Longest path calculation
Using Isolate Path to analyze a schedule

Highlight and filter critical tasks and longest path

For a more hands-on experience, navigate through the player for an interactive walk-through, or if you prefer a more detailed approach, scroll down for a step-by-step guide:

Highlight Critical Tasks and Longest Path:

1. On the Gantt Chart, click on Display to open the dropdown list
2. Click on the respective toggle to active either Critical Tasks or Longest Path
3. Once activated, ALICE will highlight respective activities in the Gantt chart with RED for critical and BLUE Hatch for the longest activities.

Filter Gantt Chart by Critical Tasks, Longest Path or Total Float:

1. Click on Select to Filter to open the Filter Builder
2. In the Criticality section, select Critical Tasks, Longest Path or Total Float
   • ALICE allows to select multiple at the same time
3. Click Done to apply the filter

Critical task calculation

By default, ALICE considers tasks as critical if they have zero or less total float. Total float is calculated by the following logic:

• Start float = late start - early start
• Finish float = late finish - early finish (default)
• Total Float is the smallest number of the two calculations above

ALICE analyzes successors, predecessors, calendars, early start, early finish, late start and late finish of each activity and calculates the free float and total float. Just like in P6, your critical tasks are updated as you make updates to your projects.

In ALICE Optimize this calculation is done in two places:

1. On the Plan page, when the user makes edits to the plan and hits Reschedule
2. On the Analyze page when the user views a solution that has been generated from a scenario

By default, the float calculations treat resource logic as precedence. If desired, this setting can be toggled from the Analyze page so that resource logic is not treated as precedence for the purposes of float and criticality calculations.

In ALICE Model, this calculation is done only on the Analyze page and it also considers resource links in float calculation.

If you consider tasks with float greater than 0, you can use the filter builder to view all tasks by total float and add your desired criteria. This functionality is supported on both Gantt views in ALICE Optimize - Plan and Analyze. Read the filter section above to learn more.

Longest path calculation

The longest path is the sequence of tasks in a project schedule that determines the project's overall duration. A task will show up on the longest path if either delaying its start time or finish time would increase the overall project duration or accelerating its stat or finish time would decrease the overall project duration.

Using Isolate Path to analyze a schedule

The isolate path feature allows users to identify all the activities that are in the path of any activity. It will look at predecessors and successors of an activity that you select and show you all the activities in the network. It will show predecessors of predecessors, same for successors.

This is very helpful if you want to optimize for specific milestones and you want to identify which activities you would like to optimize in order to optimize for that specific activity. 

To isolate path, right click on any activity either on the Gantt chart or the task list and select Isolate Path.