Advanced PERT Simulator - Project Management Tool
PERT Project Simulator
Created By: Ir. MD Nursyazwi
Instructions on How To Use
Welcome to the Project Evaluation and Review Technique (PERT) simulator. This tool helps you estimate project time and cost with greater accuracy by accounting for uncertainty.
- Enter Task Details: Fill out the form with your task's name, its dependencies (by task ID, comma-separated), and three time and cost estimates for each:
- Optimistic: The best-case scenario.
- Most Likely: The most probable scenario.
- Pessimistic: The worst-case scenario.
- Add Task: Click "Add Task" to add your task to the table.
- Review Results: The simulator will instantly calculate the **expected time** and **cost** for each task. It also finds the **critical path**, which is the sequence of tasks that determines the total project duration.
- Use Probabilities: Use the "Calculate Probability" sections to determine the likelihood of finishing your project on or before a specific date or within a specific budget.
- Visualize: The **PERT Diagram**, **Cost/Time Graph**, and **Monte Carlo Histograms** provide a clear visual overview of your project's plan and resource allocation.
Data Input
Use the form below to add and manage your project tasks.
Data Output
The table below shows all your project tasks and their calculated values. You can double-click on a cell to edit it.
ID | Task Name | Dependencies | Optimistic Time | Most Likely Time | Pessimistic Time | Expected Time | Time Std Dev | Optimistic Cost | Most Likely Cost | Pessimistic Cost | Expected Cost | Cost Std Dev | ES | EF | LS | LF | Slack | Action |
---|
Project Summary
Total Expected Time: 0.00
Total Time Standard Deviation: 0.00
Total Expected Cost: 0.00
Total Cost Standard Deviation: 0.00
Critical Path
Tasks on the critical path have zero slack and determine the project's total duration.
Calculate Probability of Completion (Time)
Based on the total project time and standard deviation, you can find the probability of completing the project by a specific deadline.
Calculate Probability of Completion (Cost)
Find the probability of completing the project within a specific budget.
Chart and Diagram
These visuals help you understand the relationships and scale of your project tasks at a glance.
Task Expected Cost vs. Expected Time
PERT Diagram
Monte Carlo Simulation
Run a simulation to generate a probability distribution of possible project outcomes.
Science Explanation
What is PERT?
PERT, or **Project Evaluation and Review Technique**, is a statistical method used in project management to analyze and represent the tasks involved in a project. It helps in planning and scheduling projects by estimating the time and cost required to complete each task.
Unlike simple project management methods that use a single estimate, PERT considers three time estimates for each task to account for uncertainty:
- Optimistic Time: The minimum possible time a task is expected to take, assuming everything goes perfectly.
- Most Likely Time: The most probable time a task will take.
- Pessimistic Time: The maximum possible time, assuming significant setbacks.
The PERT Formulas
The core of PERT is the calculation of a **weighted average** for the expected time and the **variance** for each task. The most likely time is given a weight of four, while the optimistic and pessimistic times have a weight of one, reflecting the higher probability of the most likely scenario.
To find the expected time for a task, you use a weighted average. The formula gives four times the weight to the most likely time, adding it to the optimistic and pessimistic times, and then dividing by six.
The time standard deviation, which measures the uncertainty of the estimate, is calculated by taking the difference between the pessimistic and optimistic times and dividing it by six.
A similar set of calculations is used for cost, replacing the time variables with their cost counterparts.
The Critical Path
The **critical path** is the longest sequence of tasks that must be completed on time for the entire project to be completed on time. Any delay on a task on the critical path will delay the entire project. Tasks not on the critical path have **slack**, meaning they can be delayed without affecting the project's overall completion date.
Probability Calculation (Z-score)
The probability calculation uses the **Standard Normal Distribution** (also known as the Z-distribution) to determine the likelihood of finishing by a target time. We calculate a **Z-score** for the target time, which tells us how many standard deviations away the target is from the expected completion time.
A higher Z-score indicates a higher probability of completion.
Monte Carlo Simulation
While the standard PERT method gives a single expected value, the **Monte Carlo Simulation** provides a more robust analysis of risk. It works by running a large number of trials (simulations) to model the outcomes. For each trial, a random value for each task's duration and cost is selected from a normal distribution based on the task's expected value and standard deviation. The project's total time and cost are calculated for each trial, and the results are compiled into a distribution (a histogram). This gives you a clear visual of the most probable range of project completion times and costs, as well as the likelihood of extreme scenarios.
References
To learn more about project management and the techniques used in this simulator, check out these excellent books:
- A Guide to the Project Management Body of Knowledge (PMBOK Guide) - The foundational guide for all project management professionals, providing an overview of best practices.
- Project Management Absolute Beginner's Guide - A great starting point for anyone new to project management, covering key concepts and techniques in a simple, easy-to-understand way.
- The New Project Management: Tools & Techniques for the Modern PM - This book offers practical tools and techniques, including modern approaches to project planning and execution.
- The Fast Forward MBA in Project Management - Provides a quick and effective overview of the essential skills and knowledge needed to manage projects successfully.
Other Simulators
While PERT is a powerful tool for projects with uncertain timelines, other simulators and project management techniques exist that serve different purposes:
- Advanced WBS Simulator - A tool for creating and managing a **Work Breakdown Structure (WBS)** for complex projects.
- ROI Calculator (Return on Investment) - Calculate the **return on investment (ROI)** for various projects and investments.
- Motor to Generator Simulator - Simulate the conversion of a motor's rotation into electrical energy, demonstrating the principles of **electromagnetic induction**.
- Piezoelectric Effect Simulator - Explore how mechanical pressure on certain materials can generate an **electric charge**.
- Triboelectric Effect Simulator (Static Electricity) - Demonstrate the creation of **static electricity** through friction between different materials.
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