Study guide
2.2 Activity Durations, Productivity, and Work Calendars
AACE Planning and Scheduling Professional PSP
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1 Chapter 0: Introduction & AACE PSP Exam Structure
0.1 Current AACE PSP Exam, Eligibility, and Certification Facts 0.2 Planning and Scheduling Professional Roles and Competencies 0.3 Cost Engineering and Scheduling Terminology per RP 10S-90
2 Chapter 1: Scope Definition & Planning Fundamentals
1.1 Work Breakdown Structure (WBS) Architecture & RP 33R-15 1.2 Organization & Resource Breakdown Structures (OBS, RBS, RAM) 1.3 Project Planning and Activity-Logic Development 1.4 Contract Requirements and Delivery Constraints 1.5 Stakeholder Identification, Needs, and Plan Review 1.6 Constructability Methods and Value Engineering 1.7 Resource Identification and Project Variables 1.8 Scope, Goals, Project Plan, and Phase Definition 1.9 Cost Breakdown Structure and Cost Estimate Development 1.10 Phase Relationships, Baseline Plan, Forecasts, and Risk/Recovery Planning
3 Chapter 2: Critical Path Method Mechanics & Network Logic
2.1 Activity Definition and Logic Relationships 2.2 Activity Durations, Productivity, and Work Calendars 2.3 Forward and Backward Pass Mathematical Mechanics 2.4 Float Calculations and Critical-Path Identification
4 Chapter 3: Advanced Network Techniques & Schedule Constraints
3.1 Schedule Constraints and Their Impact on Dates and Float 3.2 Advanced Logic Modeling: Ladders and Fragnets 3.3 Schedule Levels of Detail and Schedule Basis Documentation 3.4 Schedule Scope and Schedule Specification 3.5 Breakdown-Structure Relationships and the Cost Estimate Model 3.6 Stakeholder Feedback and Types of Schedules 3.7 Activities, Milestones, Schedule Quality, and Basis Documentation
5 Chapter 4: Resource Management & Leveling
4.1 Resource Planning, Allocation, and Histograms 4.2 Resource Leveling vs. Resource Smoothing 4.3 Cumulative Resource S-Curves & Productivity Tracking
6 Chapter 5: Baseline Management & Schedule Updating
5.1 Baseline Establishment, Forecasts, and Controlled Revision 5.2 Progress Measurement and Data Date Mechanics 5.3 Out-of-Sequence Logic: Progress Override vs. Retained Logic 5.4 Schedule Update Review and Quality Verification per RP 53R-06 5.5 Cost/Resource Management, Schedule Change, and Feedback 5.6 Acceleration and Recovery Scheduling per RP 54R-07 5.7 Control Schedules, Variance Analysis, Forecasts, and Management Summaries
7 Chapter 6: Schedule Risk Analysis & Monte Carlo Simulation
6.1 Schedule Risk Principles, Risk Drivers, and Three-Point Estimates 6.2 Monte Carlo Simulation, Criticality, Correlation, and Merge Effects 6.3 Risk Outputs, Confidence Dates, Sensitivity, and Contingency
8 Chapter 7: Earned Value & Earned Schedule Management
7.1 Earned Value Foundations: PV, EV, AC, and Variances 7.2 Traditional EV Performance Indices & Late-Project Quirks 7.3 Earned Schedule (ES) Theory, SV(t), and SPI(t) 7.4 Independent Schedule Forecasting & IEAC(t)
9 Chapter 8: Forensic Schedule Analysis & Delay Claims
8.1 Delay Classification, Criticality, and Contract Questions 8.2 RP 29R-03 Taxonomy, Data Validation, and Method Selection 8.3 TIA, Windowed Analysis, and Subtractive Models 8.4 Concurrency, Pacing, and Float: Technical Analysis Before Entitlement
10 Chapter 9: Executive Communication & Practical Scenario Applications
9.1 Official PSP Memo Writing Framework 9.2 Structured Technical Problem-Solving for PSP Scenarios 9.3 Current Exam Strategy and Core Calculation Review
2.2 Activity Durations, Productivity, and Work Calendars
Key Takeaways Explain This Topic AI
Duration estimates should trace to quantity, production rate, crew, method, workfront, calendar, and risk assumptions.
Adding resources reduces duration only when work is divisible and the workfront, supervision, equipment, and workflow can support the larger crew.
Calendars define working time and can differ by trade, shift, location, season, or operating restriction.
Anticipated weather treatment must follow the contract or specification and use a documented, project-appropriate basis; no single calendar method is universally required.
Multiple calendars and relationship lags can make date and float interpretation non-intuitive, so reviewers should trace dates in actual working time.
Last updated: October 2026
2.2 Activity Durations, Productivity, and Work Calendars
An activity duration is a forecast of working time under a stated execution basis. AACE RP 32R-04 concerns determining activity durations. A reviewable estimate connects the duration to scope quantity, production rate, crew composition, shifts, method, access, learning, congestion, and calendar.
Quantity and production
A basic relationship is:
Duration = Quantity Production per working day \text{Duration} = \frac{\text{Quantity}}{\text{Production per working day}} Duration = Production per working day Quantity
If production is expressed through labor-hours:
Required labor hours = Quantity × Labor hours per unit \text{Required labor hours} = \text{Quantity} \times \text{Labor hours per unit} Required labor hours = Quantity × Labor hours per unit
Duration = Required labor hours Crew size × Hours per shift × Shifts per day \text{Duration} = \frac{\text{Required labor hours}}{\text{Crew size} \times \text{Hours per shift} \times \text{Shifts per day}} Duration = Crew size × Hours per shift × Shifts per day Required labor hours
Suppose 1,200 cubic yards require 0.40 labor-hours per cubic yard. Total effort is 480 labor-hours. A six-person crew working eight hours per day supplies 48 labor-hours per day, producing a ten-working-day arithmetic duration. The estimate is credible only if the rate already reflects placement method, equipment, workfront, curing interfaces, inspection, and crew balance.
Resource-duration judgment
The fixed-work equation can illustrate a scenario, but actual production rarely scales perfectly. Doubling one craft may create waiting, congestion, supervision limits, equipment shortages, or unequal crew balance. Some work cannot be divided, and some durations are controlled by physical processes, reviews, transport, or calendar windows rather than labor effort. State whether duration is resource-driven, quantity-driven, fixed by an external process, or based on expert judgment.
Calendars
A calendar defines working and nonworking time: workweek, shifts, holidays, planned outages, seasonal restrictions, or other allowed windows. Different activities may use different calendars. Procurement expediting may use a five-day office calendar, fabrication a six-day shop calendar, and commissioning a continuous operating calendar.
Relationship lag also needs a calendar basis. A seven-day cure stated in calendar days differs from seven working days on a five-day calendar. Document which calendar controls a lag or model the waiting period as an activity when responsibility and status matter.
Anticipated weather
Weather treatment is project-specific. The contract or schedule specification may require anticipated adverse-weather days in calendars, explicit allowance activities, productivity adjustments, risk analysis, or another method. Use a relevant historical source and period, adjusted for location, season, work type, and threshold. A generic “ten-year average” is not automatically correct for every project, and assigning the same weather calendar to indoor and outdoor work can be misleading.
Keep normal anticipated conditions distinct from exceptional events as the governing documents define them. Document the source, analysis period, monthly allocation, affected work, and any double-counting controls. If duration rates already include normal weather loss, adding the same loss again as nonworking days will overstate the allowance.
Multi-calendar effects
When a path crosses calendars, elapsed calendar time and working-day float can appear to change at the interface. Software may report float using activity or relationship-calendar rules that vary by product and configuration. Review the actual dates and working periods rather than assuming one float number has identical meaning across all activities.
For a zero-based calculation, a duration of six working days starting at time zero finishes at time six. For inclusive day numbering, an activity starting on Day 1 and lasting six working days finishes on Day 6. State the convention before doing hand calculations.
Duration-review checklist
Trace quantity and productivity to an estimate, record, or responsible expert.
Confirm crew and equipment are available when scheduled.
Check workfront, access, supervision, safety, and congestion.
Verify calendars, shifts, holidays, weather, and restrictions.
Separate working duration from waiting, review, cure, or delivery time where useful.
Compare production assumptions with actual trends during updates.
Re-estimate remaining duration from current conditions rather than mechanically subtracting elapsed time.
A good duration is not merely mathematically neat. It is an explainable forecast of how long the defined work will take under the planned method and calendar.
Applied review: reconcile original and remaining duration
Original duration records the planned working time at baseline. Remaining duration is a current forecast from the data date. Do not calculate remaining duration solely as original duration minus elapsed time when actual production, quantity, access, method, or crew has changed. Re-estimate the remaining scope using the best current information and explain the variance.
Check units before applying a rate: labor-hours per unit, units per crew-day, calendar days, and working days are not interchangeable. If two calendars interact, inspect the actual dates around weekends, holidays, shifts, and lag periods. A one-line formula is useful only after its quantity, capacity, calendar, and feasibility assumptions are consistent.