Planning and scheduling sequence construction tasks, dependencies, and durations to hit milestones.

Scope (planning & scheduling)

This page covers time planning for construction: activity lists, dependencies, calendars, and the critical path that drives completion. In South Africa, contracts often reference JBCC programme clauses and submission rules for master programmes. The calculator adds two serial task durations—real schedules need full CPM/PERT logic, lags, milestones, and resource levelling in scheduling software.

Serial path length (minimal)

  1. Confirm activities A and B are in finish-to-start sequence with no overlap (illustration only).
  2. Enter durations in working days consistent with your calendar (5-day week vs 7-day, holidays).
  3. Sum gives the length of this two-activity chain; project duration is driven by the longest path through the full network.
  4. Baseline the approved programme and track progress against it for claims and extensions of time.

Construction / Project Engineering — Planning & Scheduling

Logic, duration, and the critical path—turn scope into a time model you can defend.

Introduction

Planning defines what must happen; scheduling places it on a timeline with dependencies and resources. Critical Path Method (CPM) finds the longest path of driving activities; float shows where delay may not slip the end date. Gantt charts communicate the programme; network diagrams show logic. Good schedules align procurement, inspections, and weather risk windows.

Gantt chart with multiple tasks plotted on a time axis
Gantt chart example (tasks vs time). See licence on Wikimedia Commons
Annotated Gantt chart showing timeline, tasks, and dependencies
Gantt chart anatomy (labels and structure—verify logic in your own models). See licence on Wikimedia Commons

What scheduling delivers

  • Baseline programme — agreed sequence and dates for contract reference.
  • Look-ahead windows — near-term coordination of trades and interfaces.
  • Delay analysis input — as-built logic and impacts for EOT claims.
  • Resource smoothing — peak labour and plant within site limits.

Contracts and practice (South Africa)

Programme submissions, revisions, and float ownership follow the employer’s contract (often JBCC-based). Agree reporting period, % complete rules, and whether schedules are resource-loaded. Align calendar with regional working norms and any seasonal restrictions.

Serial chain (two tasks, illustration)   T ≈ DA + DB   (same calendar basis).

Notation (common)

  • FS / SS / FF — finish-to-start, start-to-start, finish-to-finish links.
  • TF / FF — total float and free float on an activity.
  • Lag — mandatory wait between predecessor and successor.
  • WBS — work breakdown structure feeding activity IDs.

Examples in practice

  • Structural frame: follow-on trades gated by inspections and cure times.
  • Services: coordination of ceiling closure with MEP testing.
  • External works: weather windows and seasonal planting.
  • Commissioning: sequential energisation and handover milestones.

Calculator — serial duration

Enter duration A and duration B in days for two tasks in series. Output is A + B—not project duration unless this is the only path.

T = DA + DB   (serial chain)

Two linked tasks (illustration)

Serial duration T = DA + DB for two finish-to-start activities (same calendar).

Key terms

Critical path
Longest driving path through the network; zero total float on that path in basic CPM.
Milestone
Zero-duration event used for approvals, handovers, or sectional completion.

Software and scheduling

Enterprise scheduling uses CPM engines, calendars, and comparison to baseline. Examples (official sites):

  • Bentley SYNCHRO — 4D construction modelling and scheduling.
  • Microsoft Project — desktop scheduling and linking to Microsoft 365.
  • CCS — Candy project control (common in Southern Africa).
  • Procore — construction management with schedule integration.

No product endorsement—use the tool your contract and employer mandate; export formats and revision history must support dispute resolution if needed.

Diagram sources

Educational figures. Files in Images/planning-scheduling/ were downloaded from Wikimedia Commons into this repo (not copied from other topic folders). Confirm licence on each Commons file page before reuse.