Build Your First Project Plan in Microsoft Project: Tasks, Dependencies and Milestones

6. Link the tasks, which is where a list becomes a plan

Dependencies are the whole point of the tool. The quickest way to enter them is to type task ID numbers straight into the Predecessors column.

Typing 2 into row 3 creates a Finish-to-Start link: task 3 starts when task 2 finishes. That is the default and it covers most real work. The chart immediately redraws as a staircase with arrows showing what drives what.

There are four relationship types, and in practice you will use the first one almost exclusively.

Finish-to-Start (FS). The wall must be built before it is painted. The normal case.

Start-to-Start (SS). Two tasks kick off together, useful for work running in parallel from a shared trigger.

Finish-to-Finish (FF). Two tasks need to land at the same time, common where testing must finish with the build it is testing.

Start-to-Finish (SF). Rare. If you think you need it, you almost certainly want SS or FF.

Lag goes in the same column. Look at rows 8 and 10 in the screenshot: 7FS+5 days and 9FS+5 days. Those are procurement waits. Furniture is ordered, then five working days pass before it arrives, and nobody is doing any work in between. Lag models waiting properly, which beats the common workaround of inventing a fake task called "wait for delivery".

With the links in, Project has calculated the real schedule: Plan approved lands on 12/10/2026, Furniture delivered on 21/10/2026, and the plan finishes on 05/11/2026. The three phases roll up to 6 days for Discovery, 10 days for Prepare and 8 days for Move and handover, against a total project duration of 24 working days. Not one of those numbers was typed in.

7. Read the milestones

Milestones are checkpoints with no work in them: contract signed, system live, sign-off received. They are the 0d rows from step 4, and Project draws them as diamonds.

All three now sit on dates Project worked out: 12/10, 21/10 and 05/11. A sponsor who will never open a seventeen-row plan will happily read three diamonds and a finish date.

Link your milestones like any other task. An unlinked milestone is decoration: it sits on whatever date it was created on and stays there while the work around it moves, which is worse than not having it at all.

8. Look at the critical path before you show anyone

On the Gantt Chart Format tab, tick Critical Tasks.

The red chain is the sequence that determines the finish date. In our move that is tasks 2, 3, 4, 5, 9, 10, 13, 14, 15, 16 and 17: requirements, floor plan, landlord, cabling, then the whole move weekend and handover run. If any of those slips by a day, 10 November becomes 11 November.

The blue tasks are the interesting part. Order furniture, Furniture delivered and Book the removals firm are not critical, which means they have float: room to slip before they affect anything.

Here is the detail almost every guide gets wrong. That float is not one shared number. The furniture chain, tasks 7 and 8, carries 3 days of total slack. Book the removals firm carries 11 days, because it feeds the move weekend alongside Pack and label, and Pack and label is the driving predecessor. So the removals booking can drift for over two working weeks before it bites, while the furniture order cannot. Read each figure off the Total Slack column rather than assuming one value covers everything that is blue.

This is the single most useful view in the tool. It is the answer to "where do I put my attention this week", and it is why a plan is worth building properly rather than drawing in PowerPoint.

9. Set a baseline, or you will never be able to prove what changed

Go to Project, then Set Baseline. Choose Baseline, leave it on Entire project, and click OK.

A baseline is a snapshot of the plan as promised. Without one, Project only ever shows you the current plan, and the current plan always looks reasonable, because it has quietly absorbed every slip so far. The baseline is what lets you say "we are three days later than we said" instead of "it feels like we are behind".

Set it once the plan is agreed and before work starts. Re-baseline only when the plan is formally changed, never when it slips. A baseline you reset every time reality intrudes measures nothing.

10. The slip test: proof you built a plan and not a picture

This is the test worth running before any plan goes to a sponsor. Take one task in the middle of the plan and make it longer. We changed task 10, Cabling installed, from 4d to 7d. Nothing else was touched.

Then switch to View, Tracking Gantt, so the grey baseline bars sit behind the rescheduled ones.

Three working days added to one task, and the plan responded on its own: Cabling installed now finishes 29/10 instead of 26/10, Pack and label moves to 30/10, the move weekend goes to 03/11, and Office open moves from 05/11/2026 to 10/11/2026. The Finish Variance column reads 3 days, and the grey baseline bars show exactly where every task was supposed to be.

Note that the plan slipped three working days, not three calendar days, and the finish moved by five calendar days because a weekend sits in the middle. This is precisely the arithmetic people get wrong in their heads and in spreadsheets.

If your own plan does that, you have built a schedule. If your dates sit still, something is manually scheduled or a date was typed somewhere, and it is worth finding before a sponsor does.

The four mistakes that cause almost every broken plan

Leaving tasks manually scheduled. The dates hold still and the plan silently stops working. Check the status bar and the Task Mode column.

Typing start or finish dates. Every one creates a constraint, and constraints override the logic you built. If a task will not move, this is usually why.

Typing durations onto summary rows. It breaks the roll-up, and the phase then reports a length that does not match the work inside it.

Never setting a baseline. Without one you can describe a slip but you cannot measure it, and the plan quietly rewrites its own history every time you save.

Learn it properly, with a trainer in the room

Everything above is roughly a day's work with someone on hand to answer "why did that date jump?" at the moment it jumps. That question is where the real learning is, and it is very hard to get from a manual.

Our Microsoft Project Introduction course covers exactly this ground hands-on: scheduling modes, durations and estimates, dependency types and lag, summary structure, milestones, the critical path, baselines and tracking. Project Advanced goes on to resources, costs, levelling, custom fields and reporting across multiple plans.

Both run as scheduled online sessions or in person at your offices anywhere in the UK, and we regularly run them as a closed course for a single team, built around scenarios that mirror the projects your team actually runs. Tell us what you are planning and we will tell you which course fits.