Schedule data
Schedule data is the detailed information that supports and explains the project schedule, such as activity attributes, dependencies, calendars, assumptions, constraints, resource needs, and reserves. It provides context for dates and logic, enabling forecasting, what-if analysis, and informed decisions.
Definition
See the definition above; the sections below focus on applying and analyzing schedule data.
Key Points
- Schedule data goes beyond start and finish dates to include logic, attributes, calendars, reserves, and underlying assumptions.
- It enables building, validating, analyzing, and maintaining the schedule model over the project life cycle.
- Analysis of schedule data supports critical path, float, resource, what-if, and risk-informed evaluations.
- Baselined schedule data should be versioned and traceable; changes follow integrated change control.
- Quality depends on sound logic and accurate calendars/estimates, not on tool-generated charts alone.
- Clear organization of schedule data improves communication, forecasting, and decision-making.
Purpose of Analysis
To confirm that the schedule model is credible, detect logic and resource issues early, forecast realistic completion dates, and inform decisions on trade-offs among scope, time, cost, and risk. Analysis of schedule data reveals drivers of timelines and supports effective scenario planning and communication.
Method Steps
- Clarify the analysis objective (e.g., forecast finish date, identify slippage causes, test a scenario).
- Gather the current schedule data set: activity attributes, relationships, calendars, resource assignments, constraints, assumptions, reserves, and progress updates.
- Validate data quality: check logic completeness, avoid open ends, confirm calendars, and verify estimate realism.
- Analyze network logic: determine critical path, near-critical paths, and total/free float; look for negative float causes.
- Assess resource loading and calendars: identify overallocations, resource-driven criticality, and opportunities to level or re-sequence.
- Compare against baseline: evaluate variances and trends; integrate EVM schedule indicators if used (e.g., SPI for trend insight).
- Run what-if scenarios: test sequencing changes, resource options, and reserve usage; consider risk-influenced durations.
- Synthesize findings: highlight drivers, constraints, risks, and recommended actions; update repositories and submit change requests if needed.
Inputs Needed
- Schedule baseline and current schedule model.
- Activity list and attributes, dependency logic, and leads/lags.
- Resource assignments and calendars (organizational and project).
- Duration and effort estimates, productivity assumptions, and buffers/reserves.
- Assumptions and constraints log, change log, and risk register.
- Progress data: actual starts/finishes, % complete, and performance trends or EVM metrics.
Outputs Produced
- Updated schedule data set with corrected logic, calendars, or attributes.
- Analysis results: identified critical/near-critical paths, float profile, and resource bottlenecks.
- Forecasts and scenarios, possibly with confidence ranges or risk adjustments.
- Recommended actions and change requests to update the baseline if required.
- Communications: dashboards, narratives, and assumptions updates for stakeholders.
Interpretation Tips
- Look beyond a single critical path; near-critical paths and resource-critical chains often drive risk.
- Negative float usually signals constraints or logic errors; fix the cause rather than forcing dates.
- Validate that calendars and resource availability align with reality; small calendar errors can skew results.
- Use SPI trends for directional insight, but rely on network logic and actuals for precise forecasting.
- Document key assumptions behind durations and sequences; they explain variance and support decisions.
Example
A project shows a two-week slip. Reviewing schedule data reveals a finish-no-later-than constraint on a non-critical task and an overallocation on a key resource. Removing the unnecessary constraint and reassigning work based on resource calendars shifts float and restores the original completion date without overtime.
Pitfalls
- Relying on Gantt visuals without examining underlying logic and calendars.
- Excessive date constraints that hide true float and create negative float.
- Poor data hygiene: open-ended activities, missing predecessors/successors, or stale estimates.
- Ignoring resource availability and calendars, leading to infeasible plans.
- Failing to version and control changes to baselined schedule data.
- Overconfidence in single-point forecasts without scenario or risk analysis.
PMP Example Question
Which artifact should the project manager analyze to understand calendars, assumptions, dependencies, and reserves that explain how dates in the schedule were derived?
- Schedule baseline.
- Schedule data.
- Stakeholder register.
- Issue log.
Correct Answer: B — Schedule data.
Explanation: Schedule data contains the detailed information behind the schedule model, including logic, calendars, assumptions, and reserves, enabling analysis and forecasting beyond dates alone. The baseline is the approved version of the schedule, not the full supporting detail set.
HKSM