Forecasting and what-if analysis

1. Click AI Chat in the toolbar to open the assistant.
2. Ask a forecasting question in plain English.

Questions that work well:

• "Based on current progress, when is this project likely to finish?"
• "Which tasks are most likely to push out the finish date, and why?"
• "Give me an optimistic and a pessimistic finish date."

The forecast is the AI reasoning over your live schedule: task names, dates, progress, and dependencies, including the pace of work completed so far. There is no separate statistical engine behind it, so treat the answer as an informed reading of your plan rather than a guarantee.

The first structured scenario models a task finishing late. Name the task and the delay, and the AI cascades the slip through your dependency chain.

1. Open AI Chat.
2. Ask, for example, "What happens if task 3.1 slips by 5 days?" You can refer to tasks by the outline numbers shown on the chart, like 3.1 or 2.4, or by name. If no task has "Phase 2" in its name, "Phase 2" means the second row at the top level of the plan, when that row is a phase.
3. Read the result. Under the AI’s explanation, Ganttastic lists each task that moves, how many working days it moves and its new dates, then the new projected end date. The app works these numbers out from your own schedule and work calendar. The list starts with the tasks that move most and shows up to 10 of them, followed by a line such as "and 4 more tasks" when more move.

The second structured scenario models a person or team being unavailable for a period. For example: "What happens if Sam is unavailable from 1 June to 14 June?" The AI looks at the tasks assigned to that person in the window and reports what is at risk of slipping.

The person must be in your project’s resource list and assigned to tasks. The assistant reads the resource list and the assignments only when your question names one of the project’s resources in full (a resource called Sam Lee needs "Sam Lee", not just "Sam") or uses a word such as who, team, assigned, resource, or person. A project with no owners assigned cannot run this scenario meaningfully; see working with tasks for assigning owners.

Unlike a task slip, this answer comes from the AI alone. Ganttastic does not calculate the dates for it, so check the tasks it names against the chart. The reply still carries the Simulated label, and nothing in your project changes.

What-if analysis is read only by design. It projects the impact of a change without touching a single date. When you decide to act on a scenario, either edit the tasks directly on the chart, or ask the AI assistant to make the change and accept it in the preview.

After you build a plan with the AI Project Wizard, the suggested prompts in chat include a what-if example about a phase slipping, which is a quick way to try the feature on a fresh plan.

• No baseline comparisons. Baseline data is not sent to the chat model, so the AI cannot tell you whether you are ahead of or behind your baseline. Use baselines and variance for that.
• Task slip and resource unavailability are the two structured scenarios. Other hypotheticals get a free text answer without the same cascading calculation.
• The assistant carries only your 8 most recent messages as context, so restate the key facts in a long conversation.
• If an analysis takes longer than 30 seconds, the chat says it is still working. After 2 minutes with no reply it stops waiting and a Retry button appears. The request may still finish and count toward your AI usage.
• The AI sometimes notes when its confidence is low, but do not rely on it always doing so. Sanity check big conclusions against the chart before sharing them.

• Before you commit to a plan: slip the riskiest task and see how far the finish date moves.
• Daily team meetings: turn "task 3.1 is running late" into a concrete downstream impact you can act on the same day.
• Resource planning: check what two weeks of leave does to the schedule before approving it.
• Stakeholder conversations: when someone asks for one more thing, simulate the delay before you agree to a date.