Why are some or all of my tasks marked as "critical" even though I don't consider them to be critical?
A critical task is determined mathematically by Project Insight as any task that directly impacts the scheduled end date of the project. In other words, increasing the duration of a critical task by one day will increase the total duration of the project by one day.
It is not uncommon for a project manager to schedule a project and see critical task indicators on tasks that they may not have intuitively deemed as critical, in the dictionary sense of the word "critical." This may be the result of a dependency or duration value which does not accurately reflect the normal project process, in which case corrections to the project should be made. It may also be simply that the mathematical calculation for a critical task is not as important to the project as those tasks that the project manager knows intuitively to be the highest risk activities within the project.
If you do think that some of the tasks on your project should be removed from the critical task status, take a closer look at your schedule and dependencies to determine where to make the appropriate changes. It may be a simple matter of changing a predecessor relationship that is not absolutely necessary. Maybe you normally want the schedule to enforce one task's completion before another starts, but it is not an absolute dependency. In the example below, all tasks are on the critical path.
Once the project manager realized that they often begin the document writing prior to the complete gathering of the materials, the adjustment was made to allow for the document writing task to begin as soon as the budget was approved. Gathering the materials will take longer than writing the documents, but both tasks must finish before the first revision can be compiled. As a result of this correction to the work process, write documents has some "float" time, additional duration that the task can utilize without impacting the end date for compiling the first revision. As a result, Write Documents was removed from the critical path, changing the task time line indicator from red to blue.