# Construction Project Planning ## Table of Contents - [[#Overview]] - [[#Project Life Cycle]] - [[#Scope Definition]] - [[#Work Breakdown Structure WBS]] - [[#Scheduling Methods]] - [[#Critical Path Method CPM]] - [[#Gantt Charts]] - [[#PERT Analysis]] - [[#Resource Allocation and Levelling]] - [[#Procurement Planning]] - [[#Risk Management]] - [[#Earned Value Management EVM]] - [[#Communication and Reporting]] - [[#Software Tools]] - [[#Practical Notes for Architects]] - [[#References and Standards]] --- ## Overview Construction project planning is the systematic process of defining project objectives, establishing scope, scheduling activities, allocating resources, and establishing control mechanisms to deliver a construction project within agreed parameters of time, cost, quality, and safety. Effective planning is the single greatest determinant of project success. This article addresses the planning and monitoring of construction projects from the perspective of the design team and contract administrator, with reference to [[FIDIC Contracts]] and [[Construction Cost Estimation Methods]]. --- ## Project Life Cycle A construction project follows a defined life cycle, typically aligned with the RIBA Plan of Work or similar frameworks: | Stage | RIBA Equivalent | Key Planning Activities | |-------|--------------------|-------------------------------------------------| | 1 | Strategic Definition| Business case, feasibility study, initial brief | | 2 | Preparation and Briefing | Project objectives, constraints, site analysis | | 3 | Concept Design | Outline programme, preliminary cost plan | | 4 | Spatial Coordination| Developed programme, procurement strategy | | 5 | Technical Design | Detailed programme, resource planning, risk register | | 6 | Manufacturing and Construction | Construction programme, progress monitoring | | 7 | Handover | Commissioning programme, defects liability period | | 8 | Use | Post-occupancy evaluation, maintenance planning | Planning is not a one-time activity. The programme is developed progressively, with increasing detail at each stage. --- ## Scope Definition Clear scope definition is the foundation of all planning: - **Project brief**: Defines functional requirements, spatial needs, quality standards, budget, and programme constraints. - **Scope statement**: Formal document describing deliverables, boundaries, assumptions, and exclusions. - **Scope management**: Change control procedures to manage additions, omissions, and variations during design and construction. - **Design freeze points**: Key milestones where design decisions are locked to prevent scope creep affecting programme and cost. Scope changes after contract award are managed through variation procedures defined in the construction contract (see [[FIDIC Contracts]]). --- ## Work Breakdown Structure WBS The WBS hierarchically decomposes the total project scope into manageable work packages: ``` Level 1: Project Level 2: Phase (Design / Procurement / Construction / Commissioning) Level 3: Element (Substructure / Superstructure / Envelope / Services / Finishes) Level 4: Work Package (Foundations / Ground Floor Slab / Piling) Level 5: Activity (Excavate pile bores / Cast piles / Pile testing) ``` ### WBS Principles - Each element at the lowest level (work package) must be: - Assignable to a single responsible party. - Estimable in terms of cost, duration, and resources. - Measurable for progress monitoring. - The 100% rule: the WBS must capture 100% of the project scope, including management and quality activities. - WBS coding aligns with cost codes and specification sections for integrated project controls. --- ## Scheduling Methods ### Critical Path Method CPM CPM is the most widely used scheduling technique in construction: 1. **List all activities** from the WBS with estimated durations. 2. **Define dependencies**: Finish-to-Start (FS), Start-to-Start (SS), Finish-to-Finish (FF), Start-to-Finish (SF). 3. **Forward pass**: Calculate earliest start (ES) and earliest finish (EF) for each activity. 4. **Backward pass**: Calculate latest start (LS) and latest finish (LF) for each activity. 5. **Calculate float**: Total float = LS - ES (or LF - EF). Activities with zero total float form the **critical path**. ``` Total Float = LS - ES = LF - EF Free Float = ES(successor) - EF(activity) ``` The critical path is the longest sequence of dependent activities determining the minimum project duration. Any delay on the critical path delays the project completion. **Near-critical paths** (float < 5 working days) should also be monitored closely, as they may become critical through minor delays. ### Gantt Charts Gantt (bar) charts are the most common visual representation of construction programmes: - Horizontal bars represent activity durations plotted against a calendar timeline. - Dependencies are shown as link lines between bars. - Critical path activities are typically highlighted (red or bold). - Milestones are marked as diamond symbols at key dates. - Progress is shown by filling bars proportionally or with a tracking line. - Resources and cost loading can be displayed below the Gantt chart as histograms. ### PERT Analysis Programme Evaluation and Review Technique (PERT) addresses duration uncertainty: - Each activity is assigned three duration estimates: - **Optimistic (to)**: Best-case duration. - **Most likely (tm)**: Most probable duration. - **Pessimistic (tp)**: Worst-case duration. - **Expected duration**: ``` te = (to + 4·tm + tp) / 6 ``` - **Standard deviation**: ``` σ = (tp - to) / 6 ``` - **Variance**: σ² The probability of completing the project by a given date is calculated by summing variances along the critical path and applying the normal distribution. PERT is useful for projects with high uncertainty, such as complex refurbishment or ground works. --- ## Resource Allocation and Levelling ### Resource Allocation - Assign labour, equipment, and material resources to each activity in the programme. - Identify resource requirements over time using resource histograms. - Check resource availability against the programme to identify overloads. ### Resource Levelling - Adjust activity timing (within available float) to smooth resource demand profiles. - Avoid sharp peaks and troughs in labour demand that cause inefficiency. - Resource levelling may extend the project duration if critical activities are constrained by resource limits. ### Key Resource Categories - **Labour**: Skilled trades (bricklayers, steel fixers, electricians, etc.) with specific availability constraints. - **Plant and equipment**: Tower cranes, hoists, excavators, concrete pumps — often on time-based hire. - **Materials**: Procurement lead times for structural steel, curtain walling, specialist items. - **Subcontractors**: Availability and commitment of specialist subcontract packages. --- ## Procurement Planning Procurement strategy affects programme, cost, and risk allocation: | Strategy | Description | Programme Impact | |-----------------------|------------------------------------------------|---------------------------| | Traditional (design-bid-build) | Full design before tender | Longest overall programme | | Design and Build (D&B)| Contractor completes design | Overlapped design/construction | | Construction Management| Packages tendered as design progresses | Earliest construction start | | Management Contracting | Management contractor procures work packages | Flexible programme | | Two-stage tendering | Contractor appointed early for pre-construction | Collaborative programme | Key procurement planning decisions: - **Package breakdown**: Divide works into trade packages (structure, envelope, MEP, finishes, etc.). - **Lead times**: Identify long-lead items (structural steel: 12–16 weeks, curtain walling: 16–24 weeks, lifts: 20–30 weeks). - **Pre-qualification**: Establish approved subcontractor lists for each package. - **Tender periods**: Allow adequate time for competitive tendering (typically 4–8 weeks for major packages). --- ## Risk Management ### Risk Register A risk register is maintained throughout the project, recording: | Column | Description | |-----------------|------------------------------------------------------| | Risk ID | Unique identifier | | Description | Clear statement of the risk event | | Category | Design / Construction / Programme / Cost / External | | Probability | Likelihood rating (1–5 or percentage) | | Impact | Severity rating (1–5 or monetary/time value) | | Risk score | Probability × Impact | | Owner | Person or organisation responsible for managing the risk | | Mitigation | Actions to reduce probability or impact | | Contingency | Allowance in programme/budget for residual risk | | Status | Open / Mitigated / Closed | ### Common Construction Risks - **Ground conditions**: Unforeseen soil conditions, contamination, groundwater. - **Design changes**: Late design changes or unresolved design coordination. - **Planning and approvals**: Delayed planning consent, listed building consent, or building control approval. - **Weather**: Adverse weather affecting external works and critical path activities. - **Supply chain**: Material shortages, subcontractor insolvency, price escalation. - **Labour**: Skill shortages, industrial disputes. - **Regulatory**: Changes in building regulations, fire safety requirements. --- ## Earned Value Management EVM EVM integrates scope, schedule, and cost into a single monitoring framework: ### Key Metrics | Metric | Formula | Interpretation | |---------------------------|----------------------------------|-----------------------------| | Planned Value (PV) | Budgeted cost of work scheduled | What should have been spent | | Earned Value (EV) | Budgeted cost of work performed | Value of work completed | | Actual Cost (AC) | Actual cost of work performed | What has been spent | | Schedule Variance (SV) | EV - PV | > 0 ahead, < 0 behind | | Cost Variance (CV) | EV - AC | > 0 under budget, < 0 over | | Schedule Performance Index (SPI) | EV / PV | > 1.0 ahead, < 1.0 behind | | Cost Performance Index (CPI) | EV / AC | > 1.0 under budget, < 1.0 over | | Estimate at Completion (EAC) | BAC / CPI | Projected final cost | | Estimate to Complete (ETC) | EAC - AC | Remaining cost to complete | ### Application - Monthly EVM reporting provides early warning of programme and cost overruns. - S-curves plot PV, EV, and AC against time for visual trend analysis. - EVM is most effective when aligned with the WBS and cost code structure. --- ## Communication and Reporting - **Progress meetings**: Weekly site meetings, monthly project board meetings. - **Programme updates**: Monthly update of the construction programme with actual progress. - **Look-ahead programmes**: 3–6 week rolling programmes showing near-term activities in detail. - **Progress reports**: Monthly written reports covering programme status, EVM metrics, risks, and key decisions. - **Information Required Schedule**: Tracks design information deliverables needed by the contractor. --- ## Software Tools | Tool | Typical Use | |------------------|------------------------------------------------| | Primavera P6 | Large/complex projects, CPM scheduling | | Microsoft Project | Medium-scale projects, general scheduling | | Asta Powerproject | UK construction industry standard | | Procore | Project management platform, document control | | BIM 360 / ACC | BIM-integrated project management (Autodesk) | | Navisworks | 4D simulation (linking programme to BIM model) | --- ## Practical Notes for Architects - Provide design information in accordance with the Information Required Schedule. Late information is a primary cause of programme delay and contractual claims. - Understand the critical path of the construction programme and how design decisions affect it. For example, late finalisation of cladding details can delay envelope works, which are often critical path. - Attend site progress meetings regularly to understand programme status and coordinate design responses to site issues. - Maintain a design programme aligned with the construction programme, showing when design information for each package must be complete. - Review the risk register periodically and ensure design-related risks are managed proactively. - When issuing variations, request a programme impact assessment from the contractor before confirming the variation. - Use 4D BIM (programme linked to 3D model) for complex projects to visualise construction sequence and identify spatial conflicts. --- ## References and Standards - RIBA, *Plan of Work 2020* - PMI, *A Guide to the Project Management Body of Knowledge (PMBOK Guide)* - APM, *APM Body of Knowledge* - CIOB, *Code of Practice for Project Management for Construction and Development* - [[FIDIC Contracts]] - [[Construction Cost Estimation Methods]] - [[Health and Safety on Construction Sites]] --- #construction #planning #scheduling #CPM #EVM #riskmanagement