2.3Scheduling: Gantt chart
The essentials in 30 seconds
- Scheduling orders, Gantt visualizes: each task is a bar on a calendar — you see what happens when and the overall deadline.
- Sequencing = respecting dependencies (often finish-to-start: B starts when A ends).
- Reflex: a Gantt with no dependencies is just a wish list, not a schedule.
Running mini-case — Bilal learns everything can't start on day 1
Bilal has placed his estimated packages on a calendar: everything seems to start in parallel and fit in one month. Then he adds dependencies — testing only starts after development, training only after the tool is delivered — and the real lead time appears: two and a half months. His first Gantt was a wish list; the second, a schedule.
Sequel to cases 2.1-2.2 — Bilal orders the estimated packages over time.
1. The king of scheduling tools
The schedule orders tasks over time. Its king tool is the Gantt chart: each task is a horizontal bar placed on a calendar. At a glance, you see what happens when, what overlaps, and the overall deadline.
Bilal takes back his WBS packages with estimated durations, and positions key milestones (tool delivered, go-live).
2. Sequencing with dependencies
Building a Gantt means sequencing tasks while accounting for their dependencies (such task can only start after such other). The most common is "finish-to-start".
Chaining tasks well, forgetting no dependency, is what makes a schedule realistic rather than a mere wish list. The approach (sequencing) beats the tool.
🔎 Concrete example — 🔎 Concrete example — Wish list vs schedule
The role of dependencies.
Without dependencies: all tasks seem able to start on day 1.
With dependencies: "testing" starts only after "developing".
→ you detect unrealistic parallelisms (same person).Outcome: a visual, credible schedule.
Reflex: the approach (sequencing) beats the tool.
Section vocabulary
- Schedule
- Ordering tasks over time, with start and end dates.
Simple example: Bilal's schedule runs March to mid-May, package by package.
What it is not: a mere task list with no dates or order.
Reflex: every WBS package gets a dated place in the schedule.
- Gantt chart
- Visual schedule view: each task is a bar on a calendar axis. Readable at a glance.
Simple example: At a glance, the sponsor sees testing overlaps training.
What it is not: a risk table or a budget.
Reflex: one bar = one task placed over time.
- Dependency (link)
- Order relationship between tasks. Most frequent: finish-to-start (B starts when A ends).
Simple example: "Test the tool" only starts after "develop the tool".
What it is not: two independent tasks you can run in parallel.
Reflex: for each task: what must end first?
- Sequencing
- Logically ordering tasks by dependencies and constraints.
Simple example: Bilal chains development, testing, training, go-live.
What it is not: placing bars randomly on the calendar.
Reflex: sequencing beats the tool used.
- Gantt milestone
- Key point (diamond) with no duration marking a deadline or decision in the schedule.
Simple example: "Tool delivered" and "go-live" mark Bilal's Gantt.
What it is not: one more task with a duration.
Reflex: place decision milestones before detailing.
In practice — In practice — Building a Gantt chart
- Take WBS tasks back with their estimated durations.
- Identify dependencies: which tasks must finish before another starts (finish-to-start links)?
- Place tasks on a calendar (Gantt) respecting these dependencies; position key milestones.
- Check realism: are there unrealistic parallel tasks (same person)? Does the overall deadline hold?
Ready-to-say script — presenting your Gantt to the sponsor (1 min)
"Here is our schedule: each bar is a dated package, arrows are dependencies — testing only starts after development. Diamonds are our decision milestones. If a dependency moves, the end moves: that's why I'll alert you early."
Say to the sponsor: show dependencies + milestones, not just bars.
Copy-paste template — building my Gantt
TASKS (WBS) + DURATIONS: _______________
DEPENDENCIES (finish-to-start: B after A): _______________
MILESTONES (deadlines/decisions): _______________
PARALLELISMS CHECKED (same people?): _______________
OVERALL DEADLINE: _______________Small business / tight budget
A spreadsheet is enough: one row per task, colored bars, arrows between dependencies — no need to buy software.
Algerian SME
Bilal prints the Gantt in A3 at the office: dependencies and milestones visible to the whole team, updated every Friday.
Remote team
Gantt shared online and updated before each weekly check: everyone reads the same version, nobody works off an old schedule.
Agile / hybrid project
Keep a macro Gantt (major phases, milestones) to communicate, and steer detail in sprints — Gantt stays king in predictive.
✓ Best practices
- Always start from the WBS and estimated durations.
- Carefully identify dependencies (often finish-to-start).
- Check parallelism realism (same resources).
✗ Common pitfalls
- A Gantt without dependencies (wish list).
- Placing impossible parallel tasks (same person).
- Freezing the Gantt and never updating it during execution.
Key takeaways
- The schedule orders tasks over time; the Gantt visualizes it.
- Each task is a bar on a calendar: immediate reading.
- Sequencing means respecting dependencies (often finish-to-start).
- A Gantt without dependencies is a wish list, not a schedule.
48h Challenge — apply tomorrow
Take your estimated packages, list their finish-to-start dependencies and place them on a calendar (template above). Show it to someone: do they get the chaining?
- I can explain what a Gantt bar and a milestone are.
- I can identify a finish-to-start dependency.
- I've built a Gantt with dependencies on a real case.
Frequently asked questions
Which tool to create a Gantt chart with?
From MS Project (predictive reference) to lighter tools (online Gantt, spreadsheets, Notion, or Trello/Jira modules). For a small project, a spreadsheet or free tool is enough. What matters is the approach — sequencing with dependencies — more than the tool. A beautiful Gantt in a sophisticated tool but without real dependencies is worth less than a simple, well-built Gantt.
Is the Gantt useful in agile projects?
Less central: agile steers by iterations and backlog rather than a frozen detailed schedule. You can keep a high-level Gantt view (major phases, milestones) for communication, but detail is managed in sprints. The Gantt stays king in predictive approaches, where the sequence is planned upfront. In hybrid, a macro Gantt is often combined with agile detail steering.
Bilal's Gantt lines up flawless bars, but no arrow links them. What's wrong?