Construction project management - Guidelines, Part 2: Time Management

IS 15883 Part 2: Scope - Key Formulas, Tables & Specifications

1. Scope Variation Monitoring (Clause 6.2.4)

• Scope changes (due to design, owner instructions, unforeseen conditions, etc.) require:
  • Reworking time planning and baseline schedule.
  • Revised resource planning.
  • Impact analysis on time and cost.
  • Agreement between owner and contractor.
• Scope variation may alter the critical path and overall project timeline.
• Time monitoring/control must be based on the revised baseline schedule.

2. Productivity Standards (Clause 6.1.5)

[ \textbf{Productivity Standard (p)} = \text{Productivity Norms} \times \text{Production Efficiency Factor} ]

• Productivity Norms: Output per scheduling unit time (e.g., output/day), from IS 7272 (Part 1), CPWD, MORTH, or historical data.
• Production Efficiency Factor: Multiplier adjusting norms for actual job conditions.

3. S-Curve Time Monitoring (Annex C, Clause 6.2.5)

• Assign weightages (%) to project activities based on:
  • Criticality
  • Tender cost
  • Level of effort
• Weightages distributed across phases: Design, Procurement, Construction, Testing & Commissioning.
• Example phase weightages:

• Sub-phase distributions (e.g., Procurement):

• S-Curve plots cumulative weightage (%) vs time, useful for variance analysis and progress monitoring.

4. Baseline Schedule & Metrics Distribution

• Metrics assigned up to Level 3 WBS.
• Weightages distributed vertically (work packages) and horizontally (time phases).
• Enables planned vs actual progress comparison.

Summary Diagram: Scope Variation &

IS 15883 Part 2: Key References, Formulas & Tables Summary

1. Productivity Standards (Clause 6.1.5)

• Formula:

[ \text{Productivity standard} (p) = \text{Productivity norms} \times \text{Production efficiency factor} ]

• Definitions:
  • Productivity norms: Output per unit time (e.g., output/day), sourced from IS 7272 (Part 1), CPWD rates, MORTH data, or historical/project experience.
  • Production efficiency factor: Multiplier adjusting norms for actual job conditions.

2. Referenced Standards (Clause 1.3)

• IS 7272 (Part 1): Labour output norms
• IS 7337: Project management glossary
• IS 10400: Inventory control glossary
• IS 14580 (Parts 1 & 2): Network analysis for project management
• IS 15198: Human resource development glossary
• IS 15883 (Part 1): Construction project management general guidelines

3. Rounding Off (IS 2:1960)

• Final test/analysis values must be rounded off as per IS 2 rules, maintaining the same significant figures as specified.

4. Time Monitoring via S-Curve (Clause 6.2.5, Annex C)

• Concept: Assign weightages (%) to project activities/phases; plot cumulative planned vs actual progress (S-curve).

• Weightage Criteria:

  • Criticality of work package
  • Tendering cost
  • Level of effort

• Phases & Sample Weightages:

• S-Curve Use:

Key Definitions & Formulas from IS 15883 (Part 2)

1. Productivity Standard (Clause 6.1.5)

• Formula:

[ \text{Productivity Standard (p)} = \text{Productivity Norms} \times \text{Production Efficiency Factor} ]

• Where:
  • Productivity Norms: Output of resources per minimum scheduling unit (e.g., output/day), obtained from IS 7272 (Part 1), CPWD rates, MORTH data, or historical data.
  • Production Efficiency Factor: Multiplier adjusting norms to actual job conditions.

2. Standards Referenced for Definitions (Clause 1.3)

• IS 7337: Glossary of terms in project management.
• IS 10400: Glossary of terms in inventory control.
• IS 15198: Glossary of terms in human resource development.

3. Rounding Off (General Clause)

• Follow IS 2:1960 for rounding off numerical values, maintaining the same significant digits as specified.

4. Time Monitoring & Weightage Concept (Annex C, Clause 6.2.5)

• S-Curve: Cumulative weighted progress curve shaped like 'S' for project time monitoring.

• Weightage Allocation Criteria:

  • Criticality of work package.
  • Tentative cost.
  • Level of effort.

• Typical Weightage Distribution for Work Phases:

• Sub-Phases Example for Construction:

Summary Diagram: Productivity Standard Calculation

flowchart LR
    A[Productivity Norms] --> C[Productivity Standard]
    B[Production Efficiency Factor] --> C

This concise summary provides essential definitions, formulas, and tables for productivity and project monitoring as per IS 15883 (Part 2). For detailed tables and examples,

IS 15883 Part 2: General Principles of Time Management

Key Processes (Clause 4.4)

• Time Planning: Define scope, estimate durations, sequence activities.
• Time Monitoring: Track progress vs. schedule.
• Time Control: Update and adjust schedule dynamically.

Steps for Time Management

1. Define project scope.
2. Estimate activity durations.
3. Sequence activities with dependencies (see IS 14580 Parts 1 & 2 for network analysis).
4. Develop project schedule.
5. Monitor and control schedule continuously.

Important Considerations (Clause 4.2.1)

• Integrate time management with cost, quality, safety, scope.
• Base time frame on:
  • Past project experience.
  • Location & weather.
  • Stakeholder constraints.
  • Resource availability.
  • Quality and safety requirements.

Recommended Tools

• Use construction management software for scheduling and updates.

Basic Formula for Project Duration Estimation:

[ \text{Project Duration} = \sum \text{Activity Durations} + \text{Slack/Float} ]

Activity Sequencing Example (Precedence Diagram Method):

graph TD
  A[Start] --> B[Activity 1]
  B --> C[Activity 2]
  B --> D[Activity 3]
  C --> E[Activity 4]
  D --> E
  E --> F[Finish]

This diagram shows dependencies and parallel activities.

Summary: Time management is a continuous, integrated process involving planning, monitoring, and control, supported by network analysis (IS 14580) and software tools, while considering all project constraints and quality/safety standards.

IS 15883 (Part 2) - Time Management Key Points

Time Management Processes (Clause 4.4)

• a) Time Planning: Define scope, estimate durations, sequence activities, develop schedule.
• b) Time Monitoring: Track progress against schedule.
• c) Time Control: Take corrective actions to maintain schedule.

Steps for Time Planning

1. Define project scope.
2. Estimate activity durations.
3. Sequence activities with dependencies.
4. Develop project schedule (network diagrams, bar/Gantt charts).
5. Monitor and control schedule dynamically.

Project Classification for Time Planning (Clause 6.1.2)

Scheduling Deliverables (Clause 6.1.10)

• Prepare network diagrams and bar/Gantt charts for each sub-project.
• Link sub-project schedules into a master control schedule.
• Use Line of Balance (LOB) for repetitive or linear projects.
• Refer IS 14580 (Parts 1 & 2) for network/bar chart preparation.

Typical Time Planning Flow (Fig. 1 summary)

flowchart TD
    A[Define Project Scope] --> B[Estimate Activity Durations]
    B --> C[Sequence Activities]
    C --> D[Develop Schedule (Network/Gantt)]
    D --> E[Monitor & Control Schedule]
    E --> F[Update & Revise Schedule]

Recommendations

• Use construction management software for efficient scheduling.
• Periodically monitor and update schedules.
• Consider interfaces among disciplines for integrated scheduling.

This concise framework helps manage project time effectively per IS 15883 Part 2.

IS 15883 (Part 2) - Time Planning & Scheduling Techniques

Key Concepts:

• Time Scheduling: Assign start and finish dates using network diagrams (Precedence Diagram Method / Activity on Node per IS 14580 Part 2).
• Dependency Types (Fig. 2):
  • FS (Finish to Start)
  • FS + Lag (Finish to Start with lag)
  • SS + Lag (Start to Start with lag)
  • FF + Lag (Finish to Finish with lag)
  • SF + Lag (Start to Finish with lag)
  • FS - Lead (Finish to Start with lead)

Stepwise Approach (6.1.2 to 6.1.10):

1. Assess Project Characteristics:
   • Type (Building, Infrastructure, Industrial, Others)
   • Duration (Short <1yr, Medium 1-3yrs, Long >5yrs)
   • Value (Mega, Large, Medium, Small)
   • Execution Speed (Fast track, Normal)
2. Finalize Method Statement & Design Basis.
3. Prepare Network Diagram and perform:
   • Forward Pass (calculate Early Start/Finish)
   • Backward Pass (calculate Late Start/Finish)
4. Calculate:
   • Total Float = LS - ES or LF - EF
   • Free Float = Earliest ES of successor - EF of current activity
5. Identify Critical Path (activities with zero float).
6. Prepare Deliverables:
   • Early/Late Start & Finish dates
   • Total & Free Float
   • Critical Path & Project Duration
   • Network diagrams & Gantt charts (linked sub-projects)

Scheduling Techniques:

• Use Line of Balance (LOB) for repetitive/linear projects.
• Employ software tools for automation.

Float Calculations:

graph TD
  A[Start] --> B[Activity 1]
  B --> C[Activity 2]
  C --> D[Activity 3]
  D --> E[Finish]

  click B "FS

IS 15883 Part 2: Activity Identification & Network Preparation Key Points

1. Activity Identification (Clause 6.1.4)

• Identify all project activities clearly.
• Define dependencies among activities using types of relationships:
  • FS (Finish to Start)
  • FS + Lag
  • SS + Lag
  • FF + Lag
  • SF + Lag
  • FS - Lead

2. Network Preparation & Time Scheduling (Clause 6.1.8.2)

• Use Precedence Diagram Method (Activity on Node) as per IS 14580 (Part 2).
• Steps:
  • Prepare network diagram with activities and dependencies.
  • Perform Forward Pass and Backward Pass to calculate:
    • Early Start (ES), Early Finish (EF)
    • Late Start (LS), Late Finish (LF)
    • Total Float (TF) = LS - ES or LF - EF
    • Free Float (FF)
  • Identify Critical Path (activities with zero total float).
  • Calculate overall project duration.

3. Time Management Deliverables (Clause 6.1.10)

• Deliverables include:
  • Network diagrams and Gantt charts per sub-project.
  • Master control schedule by linking sub-project schedules.
  • Use Line of Balance (LOB) for repetitive/linear projects.
• Refer IS 14580 (Parts 1 & 2) for diagram/chart preparation.

4. Resource Scheduling (Clause 6.1.8.3)

• Estimate resources per activity/day using:

  [ \text{Resource per day} = \frac{\text{Total resource quantity}}{\text{Activity duration}} ]

• Superimpose resource data on time schedule.

• Resource levelling includes:

  • Reconciling resource needs with availability.
  • Optimizing for uniform resource usage.
  • Aligning cost schedules with cash flow.
  • Ensuring project finishes on optimum date.

Summary Table: Dependency Relationships

Key Formulas & Specifications for Time Scheduling and Dependency Relationships

(IS 15883 Part 2: 2013, Clauses 6.1.8.2 & 6.1.10)

Dependency Relationships (Types & Notations)

Time Scheduling Steps

1. Prepare Network Diagram (Precedence Diagram Method - IS 14580 Part 2)
2. Forward Pass Calculation:
   • Early Start (ES) and Early Finish (EF) for each activity
3. Backward Pass Calculation:
   • Late Start (LS) and Late Finish (LF) for each activity

Key Calculations

• Early Finish (EF):
  [ EF = ES + \text{Activity Duration} - 1 ]

• Late Start (LS):
  [ LS = LF - \text{Activity Duration} + 1 ]

• Total Float (TF):
  [ TF = LS - ES = LF - EF ]

• Free Float (FF):
  [ FF = \text{Earliest ES of successor} - EF - 1 ]

• Critical Path: Activities with Total Float = 0

Time Scheduling Deliverables

• Early & Late Start/Finish dates for each activity
• Total & Free Float values
• Critical activities and project critical path
• Project duration

Reporting & Tools

• Use Network Diagrams and Gantt Charts for visualization
• For repetitive or linear projects, use **Line of Balance (

Resource Scheduling & Levelling (IS 15883 Part 2)

Key Formulas:

1. Productivity Standard (Clause 6.1.5):

[ \boxed{ p = \text{Productivity Norms} \times \text{Production Efficiency Factor} } ]

• p: Productivity standard (output per scheduling unit, e.g., resources/day)
• Productivity norms: From IS 7272 (Part 1), CPWD, MORTH, or historical data
• Production efficiency factor: Adjusts norms to actual site conditions

2. Resource Requirement per Activity per Day (Clause 6.1.8.3):

[ \text{Resource Required} = \frac{\text{Work Quantity}}{p \times \text{Activity Duration}} ]

Resource Scheduling Deliverables (6.1.8.3):

• Daily resource amounts for each activity (manpower, material, equipment)
• Daily resource amounts for entire project duration

Resource Levelling Steps (6.1.8.3):

• Reconcile resource demand with availability
• Optimize for uniform resource usage
• Align cost schedules with cash flow
• Adjust schedules to meet optimum finish date

Time Scheduling (Clause 6.1.8.2):

• Use Precedence Diagram Method (IS 14580 Part 2)
• Dependency types: FS, FS+lag, SS+lag, FF+lag, SF+lag, FS-lead
• Calculate Early Start/Finish, Late Start/Finish, Float, Critical Path

Summary Table: Resource Scheduling Workflow

flowchart TD
    A[Estimate Productivity] --> B[Calculate Resource Requirement]
    B --> C[Prepare Network Diagram]
    C --> D[Forward & Backward Pass]
    D --> E[Superimpose Resource Data]
    E --> F[

IS 15883 Part 2: Progress Monitoring & Reporting Key Points

Common Project Metrics (Clause 6.2.5)

• Earned Value (budgeted cost of work performed)
• Manhour estimates
• Pre-agreed weightage (criticality/importance)
• Combination of above

Activity Tracking Steps (Clause 6.2.2)

• Compare actual vs planned status
• Analyze deviations & impact on schedule
• Forecast future progress
• Prepare catch-up plan if delays exist
• Monitor baseline critical path & update critical activities

Project Status Report Contents

• Planned vs achieved progress (tabular/graphical)
• Past performance & rate analysis
• Critical activities status & forecast
• Look-ahead program status

Graphical Reporting (Clause 6.2.5)

• Weighted summation of all WBS activities
• Baseline vs Actual vs Catch-up curves (see Fig. 5 & 6)
• Horizontal shift = time delay
• Vertical gap = progress shortfall

Sample Formula for Earned Value (Annex B)

[ \text{Earned Value (EV)} = \text{Budgeted Cost of Activity} \times \text{Percent Complete} ]

Typical Table for Progress Reporting (Annex C style)

gantt
    title Project Progress Monitoring
    dateFormat  YYYY-MM-DD
    section Baseline Plan
    Activity A       :done, 2024-01-01, 10d
    Activity B       :done, 2024-01-11, 15d
    section Actual Progress
    Activity A       :active, 2024-01-01, 8d
    Activity B       :active, 2024-01-13, 12d
    section Catch-up Plan
    Activity A       :crit, 2024-01-09, 4d

Summary:
Use a common metric (earned value/manhours/weightage) for all activities. Track progress daily,

IS 15883 Part 2: Time-Cost Tradeoff & Schedule Compression Key Points

1. Time-Cost Tradeoff Concept (Clause 6.1.8.4, Annex A)

• Goal: Reduce project duration (PN) to a target duration (PR) with minimal increase in direct cost.
• Approach: Buy time on critical path activities by increasing direct costs (more labor, equipment).
• Time-Cost Curve:

• Cost Slope (Cost per day saved):

[ \text{Cost slope} = \frac{C_c - C_N}{T_N - T_c} ]

2. Siemens Approximation Method (SAM) Steps

• Perform CPM to find normal project duration (PN).
• Set target reduced duration (PR), where PN > PR.
• Identify all project paths and their durations.
• Calculate cost slope for activities on critical/inadequately shortened paths.
• Calculate effective cost slope = cost slope / number of critical paths containing the activity.
• Select activity with lowest effective cost slope for crashing.
• Shorten activity by minimum of:
  • Available reduction time for activity,
  • Required reduction on critical path(s).
• Repeat until project duration ≤ PR.

3. Schedule Compression (Clause 6.3.5.1)

• Also called acceleration measures.
• Use time-cost tradeoff principles to buy time cost-effectively.
• Employ heuristics like modified Siemens method.
• Aim to meet deadlines with optimal cost increase.

4. Time Scheduling Essentials (Clause 6.1.8.2)

• Use Precedence Diagram Method (PDM) per IS 14580 (Part 2).
• Calculate early/late start & finish, float, critical path.
• Deliverables include network diagrams and Gantt charts.

Summary Table: Time-Cost Tradeoff Parameters

| Parameter | Symbol | Unit | Description | |---------------------|---------|------------|

IS 15883 Part 2: Key Points on Change Management for Schedule Acceleration

Acceleration Measures (Clause 6.3.5.1)

• Purpose: Buy time cost-effectively to meet deadlines.
• Also called: Time-cost trade-off process (Annex A).
• Method: Use heuristic algorithms like the Modified Siemens Method to find optimum acceleration.

Time Scheduling (Clause 6.1.8.2)

• Use Precedence Diagram Method (PDM) or Activity on Node (AON).
• Types of dependencies (Fig. 2):
  • FS (Finish to Start)
  • FS + Lag, SS + Lag, FF + Lag, SF + Lag
  • FS - Lead (lead time)
• Perform:
  • Forward pass (early start/finish)
  • Backward pass (late start/finish)
• Calculate:
  • Total float, free float
  • Critical path & critical activities
  • Project duration

Time Management Deliverables (Clause 6.1.10)

• Prepare network diagrams and bar/Gantt charts for sub-projects.
• Link to form a master control schedule.
• Use Line of Balance (LOB) for repetitive/linear projects.
• Refer IS 14580 (Parts 1 & 2) for scheduling standards.

Typical Forward and Backward Pass Calculations

flowchart TD
    A[Start] --> B[Activity A]
    B --> C[Activity B]
    C --> D[Finish]

    style B stroke:#f66,stroke-width:2px
    style C stroke:#f66,stroke-width:2px

Summary: Use heuristic algorithms (e.g., Modified Siemens) for optimal schedule acceleration, apply PDM/AON with dependency types, perform forward/backward pass for scheduling, and prepare linked network/bar charts

Time-Cost Tradeoff Algorithm (Siemens Approximation Method - SAM) per IS 15883 Part 2

Key Formulas:

• Cost Slope (CS):
  [ CS = \frac{C_c - C_N}{T_N - T_c} ]
  Where:

  • (C_c) = Crash cost
  • (C_N) = Normal cost
  • (T_N) = Normal time
  • (T_c) = Crash time

• Deterministic Activity Duration:
  [ T_E = \frac{q}{p \times n} ]
  Where:

  • (q) = Work quantity
  • (p) = Resource productivity
  • (n) = Number of resource groups

• Probabilistic Activity Duration (PERT formula):
  [ T_p = \frac{a + 4m + b}{6} ]
  Where:

  • (a) = Optimistic duration
  • (m) = Most likely duration
  • (b) = Pessimistic duration

SAM Algorithm Steps:

1. Calculate project normal duration (P_N) using CPM.
2. Set reduced project duration (P_R) ((P_N > P_R)).
3. Identify all project paths and their lengths (sum of normal times).
4. Find activities on critical/inadequately shortened paths.
5. Calculate effective cost slope for each activity:
   [ \text{Effective CS} = \frac{\text{Cost Slope}}{\text{Number of inadequately shortened paths containing the activity}} ]
6. Select activity with lowest effective cost slope on paths needing shortening.
7. Shorten activity by minimum of:
   • Remaining unallocated time for activity
   • Smallest shortening demand on paths containing the activity
8. Repeat until all paths meet (P_R).

Notes:

• Assumes linear time-cost relationship between normal and crash points.
• Limits exist beyond which crashing is ineffective or counterproductive.
• Useful for schedule compression with minimum cost increase.

flowchart TD
    A[Start: CPM & Project Normal Duration (PN)] --> B[Set Reduced Duration

Earned Value Management (EVM) Key Formulas & Specifications (IS 15883 Part 2)

Basic Elements:

• Planned Value (PV) or BCWS: Budgeted cost for scheduled work.
• Actual Cost (AC) or ACWP: Actual cost incurred.
• Earned Value (EV) or BCWP: Budgeted cost of work performed.

EV Calculation:

[ \text{EV} = \text{Baseline Cost} \times % \text{Complete} ]

Key Performance Indicators:

Reporting & Monitoring:

• Use common measurement parameters (EV, manhours, or weighted importance) across all WBS activities.
• Summarize project status graphically or tabularly at all WBS levels.
• Weighted summation of sub-activities generates overall project status.

Visual Summary of EVM Elements and SPI:

flowchart LR
    PV[Planned Value (PV)]
    AC[Actual Cost (AC)]
    EV[Earned Value (EV)]
    SPI[Schedule Performance Indicator (SPI)]

    PV --> SPI
    EV --> SPI
    SPI -->|SPI = EV / PV| Status{Project Status}
    Status -->|SPI > 1| Ahead[Ahead of Schedule]
    Status -->|SPI < 1| Behind[Behind Schedule]

Use EVM to:

• Track progress
• Forecast performance
• Reduce schedule and cost overruns

For detailed tables and graphical reports, refer to Annex B of IS 15883 Part 2.

IS 15883 Part 2: Sample Time Monitoring Based on Weightage Concept (S-Curve)

Key Concepts:

• Project Metric: A common parameter (weightage %) assigned to each activity reflecting its importance, cost, and effort.
• S-Curve: Cumulative planned and actual progress plotted against time, shaped like an 'S', used for time monitoring.
• Weightage Allocation Criteria:
  • Criticality/importance
  • Tentative cost
  • Effort required

Weightage Distribution (Typical Example):

Procedure:

1. Assign weightages to work packages and phases.
2. Distribute weightages horizontally over activity durations.
3. Sum weightages cumulatively to plot baseline S-curve.
4. Track actual progress similarly to plot actual S-curve.
5. Analyze deviations (vertical/horizontal gaps) for time control.
6. Prepare catch-up curves if behind schedule.

Sample S-Curve Interpretation:

graph LR
A[Baseline S-Curve] --> B[Actual S-Curve]
B --> C{Deviation?}
C -->|Yes| D[Analyze WBS Level Details]
C -->|No| E[On Schedule]
D --> F[Take Corrective Actions]

Benefits:

• Unified progress measurement.
• Visual tool for decision-making.
• Drill-down analysis at WBS levels.
• Forecast and catch-up planning.

For detailed tables and examples, refer to Annex C and Clause 6.2.5 of IS 15883 Part 2:2013.