In your post, “When to do? → Timeline” means:
Timeline = the calendar plan of the project.
It tells your team when each task starts, how long it takes, and when it must finish.
Your post says a good schedule must answer 3 things: What to do = Tasks, When to do = Timeline, Who does it = Responsibility. If one is missing, the schedule can fail. (Sarim-insight)
In Microsoft Project, “Timeline” means 5 things
1. Start Date
Example:
Excavation starts on Monday.
In MS Project, this appears in the Start column.
2. Duration
Example:
Excavation = 3 days.
In MS Project, this appears in the Duration column.
3. Finish Date
Example:
Excavation finishes on Wednesday.
MS Project can calculate this automatically after you enter start + duration.
4. Sequence / Dependency
Example from your post:
Excavation → Footing → Column. This is sequence logic. (Sarim-insight)
In MS Project, you use Link Tasks so the next task starts after the previous task finishes. Microsoft’s support page also explains linking tasks in the Gantt Chart view. (Microsoft Support)
5. Gantt Chart
The Gantt Chart is the visual timeline.
Left side = task list.
Right side = bars showing time.
Microsoft Project’s Gantt Chart view is used to create tasks, subtasks, summary tasks, and task links. (Microsoft Support)
Simple construction example
| Task | Duration | Start | Finish | Logic |
|---|---|---|---|---|
| Excavation | 3 days | Day 1 | Day 3 | First |
| Footing | 4 days | Day 4 | Day 7 | After excavation |
| Column starter | 2 days | Day 8 | Day 9 | After footing |
So the timeline answers:
“When should each team do each work?”
GC meaning
For you as a General Contractor:
Timeline is not just dates. Timeline is control.
It helps you know:
Today: What should happen?
This week: Are we ahead or behind?
This month: Will the project finish on time?
Problem: Which delay affects the whole project?
That connects to your post’s idea of critical path thinking: ask, “If this task is late, will the whole project be late?” (Sarim-insight) Microsoft also explains that the critical path shows tasks that affect the project finish date. (Microsoft Support)
Easy sentence to remember
Tasks tell WHAT to do.
Responsibility tells WHO does it.
Timeline tells WHEN to do it.