Calculators

FlowPERT | PERT Chart Manager

FlowPERT - PERT Chart Manager

FlowPERT

PERT Chart Manager - Interactive Project Planning Tool

How to Use This Tool ▼

  • Click "Add Task" to create project tasks with durations and dependencies
  • Select dependency types: Finish-to-Start (FS), Start-to-Start (SS), Finish-to-Finish (FF), or Start-to-Finish (SF)
  • Add lag time (positive) or lead time (negative) to dependencies for scheduling flexibility
  • Toggle time units between Hours, Days, or Weeks using the dropdown menu
  • Set a project start date to calculate the actual completion date
  • The critical path (longest sequence) is highlighted in red on the chart
  • Drag nodes on the chart to rearrange the visual layout
  • Click on tasks in the list to edit or delete them
  • Use pinch gestures on mobile to zoom the chart
  • Export your project data or clear all to start fresh
Quick Start Templates:
Chart Legend
Critical Path
Normal Task
Critical Link
Normal Link
SS/FF/SF
HIGH MED LOW
PERT Chart No tasks yet
Tasks
📋

No tasks added yet.
Click "Add Task" to begin.

Dependencies
🔗

No dependencies defined yet.

Simple Duration: Direct time estimate
PERT Formula: Duration = (O + 4M + P) / 6
⚠️ Delete All Tasks?

This will permanently delete all 0 task(s) and cannot be undone.

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📖 PERT Glossary
PERT (Program Evaluation and Review Technique)

A project management tool used to schedule, organize, and coordinate tasks within a project. It uses a network diagram to visualize task dependencies and identify the critical path.

Critical Path

The longest sequence of dependent tasks that determines the minimum project duration. Tasks on the critical path have zero slack and any delay directly impacts the project completion date.

ES (Early Start)

The earliest time a task can begin, based on the completion of all predecessor tasks.

EF (Early Finish)

The earliest time a task can finish. Calculated as: EF = ES + Duration

LS (Late Start)

The latest time a task can start without delaying the project. Determined through backward pass calculation.

LF (Late Finish)

The latest time a task can finish without delaying the project. Calculated as: LF = LS + Duration

Slack (Float)

The amount of time a task can be delayed without affecting the project completion. Calculated as: Slack = LS - ES (or LF - EF). Critical path tasks have zero slack.

Finish-to-Start (FS)

The most common dependency type. The successor task cannot start until the predecessor task finishes.

Start-to-Start (SS)

The successor task cannot start until the predecessor task starts. Both can run in parallel after the start.

Finish-to-Finish (FF)

The successor task cannot finish until the predecessor task finishes. Often used for parallel tasks that must end together.

Start-to-Finish (SF)

Rarely used. The successor task cannot finish until the predecessor task starts.

Lag Time

Positive delay time added to a dependency. Example: painting can't start until 2 days after plastering finishes (drying time).

Lead Time

Negative lag time, allowing a successor to start before the predecessor finishes. Shown as negative lag value.

Three-Point Estimation

A technique to calculate expected duration using three estimates: Optimistic (O), Most Likely (M), and Pessimistic (P). Formula: Duration = (O + 4M + P) / 6

Forward Pass

Calculation method moving from start to finish of the network to determine ES and EF for all tasks.

Backward Pass

Calculation method moving from finish to start of the network to determine LS and LF for all tasks.

📊 Critical Path Report
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