Project planning Study Guide

📖 Core Concepts Project Planning – Designing the schedule (e.g., Gantt chart) and tracking progress; can be done by hand or with software. Scope Definition – First step; clarifies what the project will deliver and sets the basis for selecting methods. Work Breakdown Structure (WBS) – Hierarchical grouping of task durations into work packages that are small enough to manage. Activity Network Diagram – Visual map of logical task dependencies; used to locate the critical path. Critical Path – The longest chain of dependent tasks; determines the shortest possible project duration. PERT Weighted‑Average Duration – Estimates a task’s time using optimistic (O), most‑likely (M), and pessimistic (P) cases: $$TE = \frac{O + 4M + P}{6}$$ Critical Chain Method – Adds protective time buffers to the schedule to absorb delays. Baseline Schedule – The approved schedule against which actual progress is measured. Earned Value Management (EVM) – Compares actual work & cost to the baseline, yielding schedule and cost performance metrics. --- 📌 Must Remember Scope first → defines what to plan. WBS → Work Packages → foundation for estimating resources and costs. Critical Path = longest dependent sequence → any delay here pushes the whole project. PERT formula: $TE = (O + 4M + P)/6$. Baseline = “plan”; all variance analysis is actual vs. baseline. EVM metrics (e.g., Schedule Variance, Cost Variance) come from comparing earned value to planned value. --- 🔄 Key Processes Define Scope → Write clear deliverables. Create WBS → Break project into manageable work packages. Estimate Durations → Use PERT weighted‑average or expert judgment. Build Activity Network Diagram → Link tasks by logical dependencies. Identify Critical Path → Find longest dependent path; flag as schedule risk. Add Buffers (Critical Chain) → Insert time buffers after critical chain tasks. Set Baseline Schedule → Freeze approved timeline. Track Progress → Measure actual completion against baseline; apply EVM. --- 🔍 Key Comparisons Critical Path vs. Critical Chain Critical Path: focuses on task order; no buffers. Critical Chain: adds time buffers to protect against delays. Optimistic (O) vs. Pessimistic (P) Estimates O: best‑case, assumes everything goes perfectly. P: worst‑case, assumes maximum delays. Baseline Schedule vs. Updated Schedule Baseline: fixed reference point. Updated: reflects approved changes; variance analysis compares actual to baseline, not to updated. --- ⚠️ Common Misunderstandings “Critical path is the same as the longest task.” – It’s the longest sequence of dependent tasks, not a single task. “Adding buffers makes the project faster.” – Buffers protect schedule reliability; they don’t shorten duration. “Earned value = percent complete.” – Earned value is budgeted cost of work performed (BCWP), not just a visual percent. --- 🧠 Mental Models / Intuition “Chain‑link model” – Think of each task as a link; the weakest (longest) chain determines how fast the whole rope can be pulled. “Three‑point estimate” – Visualize a triangle with O, M, P at its corners; the weighted average leans toward the most likely (four‑times weight). --- 🚩 Exceptions & Edge Cases Parallel Critical Paths – Occasionally two separate paths have identical total duration; both must be protected. Resource‑Constrained Projects – Critical path may shift when resources are limited; schedule optimization must balance resource usage. --- 📍 When to Use Which Use PERT weighted‑average when you have clear optimistic, most‑likely, and pessimistic estimates. Use Critical Chain for projects with high uncertainty or frequent delays; add buffers after the critical chain. Use Activity Network Diagram for any project with complex task dependencies; essential for critical‑path analysis. Apply Earned Value Management when you need quantitative schedule & cost performance tracking against a baseline. --- 👀 Patterns to Recognize “Longest dependent chain → schedule risk.” Spot any sequence of tasks where each depends on the previous; check its total duration. “Four‑M weight in PERT” – If a problem gives O, M, P, expect the formula with 4×M. “Buffers placed after critical chain tasks” – Look for buffer boxes in schedule charts; they indicate Critical Chain usage. --- 🗂️ Exam Traps Choosing the shortest task as “critical.” – Remember: critical = longest dependent path, not shortest single task. Applying the PERT formula with equal weights (1‑1‑1). – The correct weight is 1‑4‑1. Assuming earned value equals percent complete of the schedule. – Earned value is based on budgeted cost, not time percentage. Treating a revised schedule as the baseline for variance analysis. – Only the original approved baseline is the reference; updated schedules are separate change documents.