Construction Methods and Project Management Final Exam

Project Schedule

Contractual network diagram of planned activities: their sequence, durations, and completion conditions

Job Logic

The logical production sequence in which activities must be performed

CPM Advantages

Instant monitoring, higher productivity, and a court-admissible delay-claim document

Project Conception

Pre-production planning, production planning & scheduling, and the project scheduling phase

S-Chart (S-Curve)

Graphical total schedule that also records progress over time

Gantt / Bar Chart

Simple chart relating each task to its schedule timeline

Long-Lead Items

Materials/equipment with long procurement times, flagged for close monitoring

Progress Schedule Regimentation

Setting precedence for all milestones, meetings, inspections, deliveries, and payments

Precon Meeting

Prebid meeting of all vested parties to settle production-scheduling details

Shop Drawing Log

Tracker of received/sent shop drawings, durations, and submittal dates (reviewed by PM and owner first)

Milestone

Benchmark marking the completion of a project phase

Network Diagram

Map of all production activities plus job logic that makes a schedule operable

Scheduling Philosophy

Selection of the scheduling system, which sets the production contracting basis

Workarounds

Alternative activities substituted when the critical path hits a bottleneck

Field Scheduling

Site-level scheduling that monitors projected vs. actual progress, critical path first

Proposal Scheduling

Preliminary bar-chart schedules contractors prepare (unpaid) during bidding

PERT

Military-origin technique estimating duration via the average of optimistic and pessimistic dates

CPM

Critical Path Method; late-1950s scheduling/logic tool, modernized by James Kelly (1967)

CPM Objectives

Schedule, Control, Organize, Implement

Activity

An item of work, shown as an arrow, with or without duration

Node / Event

The start and finish point of an activity

Arrow Diagram (AOA)

Network of activities/events drawn as arrows and nodes; needs dummies

Precedence Diagram (AON)

Activity-on-node diagram; eliminates dummies and is easy to modify

Time-Scale Diagram

Simple schedule-vs-time picture for management, not for detailed control

Restraint / Dummy

Non-time-consuming logic tie showing dependency between activities

Critical Path

Longest-duration chain in the network; its activities have zero float

Early Start (ES)

Earliest time work can begin on an activity

Early Finish (EF)

ES + duration

Late Start (LS)

Latest an activity can start without affecting project duration

Late Finish (LF)

Latest an activity can finish without affecting project duration

Forward Pass

Add durations left to right; take the LARGEST number at a merge → ES/EF

Backward Pass

Subtract durations right to left; take the SMALLEST value at a merge → LF/LS

Total Float (TF)

LS − ES (= LF − EF); delay possible without delaying the project

Free Float (FF)

ES(following) − EF(current); delay possible without delaying any successor

Time-Scaled Network

Network diagram plotted against a real time axis (based on early/late start) in bar-and-arrow form

Manpower Leveling

Smoothing worker/equipment counts to a stable level to cut the cost of employment fluctuation

Employment Fluctuation

Repeated hiring/laying off that adds cost; solved by keeping employment level

Program of Work (POW)

The master plan/budget document for executing a project

Direct Costs

Mobilization/demobilization, materials, labor, supervision (3% of labor), and equipment

Indirect Costs

OCM (8% of direct), contractor's profit (8% of direct), and VAT (5% of direct+OCM+profit)

Supervision Cost

Estimated at 3% of labor cost

OCM

Overhead, Contingencies & Miscellaneous; 8% of total direct cost

Contractor's Profit

8% of total direct cost

VAT

5% of (Total Direct Cost + OCM + Contractor's Profit)

Bill of Quantities (BOQ)

Detailed list of all work-item quantities for pricing

Detailed Estimate

Priced computation of all work items

S-Curve

Cumulative progress-versus-time curve

Gantt Chart

Simple task-versus-time bar chart

Equipment Utilization

Optional record of how equipment is used over the project

Cash Flow Plan

Plan of money inflows/outflows over time, drawn from economics

Minimum Project Contents

POW, BOQ, Detailed Estimate, PERT/CPM, Time-Scaled Network, Gantt, Manpower Leveling, S-Curve, Equipment Utilization (optional), Cash Flow, Plans & Specs

PERT

Program Evaluation Review Technique; handles duration uncertainty with three estimates and statistics

Optimistic Time (a)

Minimum time an activity will take; probability about 1%

Most Likely Time (m)

Normal duration most frequently required under identical conditions

Pessimistic Time (b)

Maximum time under the worst conditions; probability about 1%

Expected Time E(t)

Weighted average duration = (a + 4m + b)/6; equals the mean μ

Variance (σ²)

Measure of spread = (b − a)²/36

Standard Deviation (σ)

Square root of variance = (b − a)/6

Standard Normal Distribution

Normal curve with mean 0 and variance 1

Z-Score

Standardized value: z = (x − μ)/SD

Path Expected Time

Sum of the expected times of the activities on the path

Path Variance

Sum of the variances of the activities on the path

Critical Path (PERT)

Path with the greatest total expected time; controls completion probability

Central Limit Idea

Sum of many activity times is approximately normally distributed

On-Time Probability

P(z ≤ (target − μ)/SD) read from the standard normal table