Overview
Schedule Planning and Development runs from decomposition to an approved baseline. You build the work breakdown structure (WBS), organizational breakdown structure (OBS) and control accounts, define activities and milestones, estimate durations, sequence them with dependencies and constraints, find the critical and near-critical paths, load and level resources, align the schedule with the program or integrated master plan, test milestones against the contract, run schedule risk analysis, gain consensus and set the performance measurement baseline (PMB).
Candidates must understand the mechanics behind each step: forward and backward passes, float types, PERT and three-point estimates, lags and leads, resource leveling versus smoothing, and why a Monte Carlo result answers a question CPM cannot. This domain consumes Domain 1's rules and produces the baseline Domain 3 measures against, so errors here show up as false variances later.
How it's tested
Expect a mix of calculation and judgment. Calculations include forward and backward passes, total and free float, PERT and three-point durations, standard deviations and the effect of lags or leveling. Judgment items ask for the BEST technique, the correct dependency type, or what to do NEXT when a milestone cannot meet the contract date.
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Network math
A small network with durations and relationship types is given; you compute the critical path, a float value or the effect of a change in one activity's duration.
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Technique fit
A situation (no history, a repeatable unit rate, high uncertainty) is described and you select analogous, parametric, three-point or PERT estimating, or CPM versus Monte Carlo analysis.
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Baseline readiness
A draft schedule has an issue such as unmet contract milestones or unloaded resources, and you choose the step that must happen before the baseline is approved.
A draft schedule shows the contract milestone met with zero float, but a Monte Carlo run gives only a 30% chance of meeting it. The sponsor wants to baseline now. Reasoning: a deterministic date with low confidence is not an achievable baseline. Present the risk results, evaluate responses or schedule reserve, and reach consensus on a baseline that meets the agreed confidence level before setting the PMB.
Tasks 12
Official tasks from the PMI outline, in outline order.
2.1 Develop the work breakdown structure (WBS), organizational breakdown structure (OBS), control accounts and work packagesDecompose scope and assign management responsibility.
- What it means
- You decompose the full scope into deliverable-oriented work packages, map them against the OBS, and form control accounts at the intersections where cost, schedule and scope are managed.
- What to understand
- A control account is a WBS element crossed with one OBS owner; it holds work packages and planning packages and is where earned value is measured and reported.
- How it shows up
- A scenario shows two managers claiming the same work, or work with no owner; the answer is to correct the WBS and OBS mapping into proper control accounts.
- Common confusion
- Confusing the WBS (scope decomposition) with the OBS (organizational responsibility) or the RBS (resource types).
2.2 Define activities and milestonesTurn work packages into schedulable activities and zero-duration milestones.
- What it means
- With subject matter experts, you decompose work packages into activities that can be estimated, sequenced and statused, and set milestones for key events and contract commitments.
- What to understand
- Milestones have zero duration and consume no resources; activities should be short enough to measure within a few status cycles and should map to one work package.
- How it shows up
- A long activity spans six reporting periods and progress is disputed; the fix is to decompose it into measurable activities or add interim milestones.
- Common confusion
- Treating a deliverable as an activity. Activities are verbs (pour footing); deliverables and work packages are nouns (foundation).
2.3 Estimate activity durationsUse experts and techniques such as analogous, parametric, three-point and PERT.
- What it means
- You estimate how long each activity will take in working periods, selecting the technique that suits the data available and documenting the basis of estimate.
- What to understand
- Triangular three-point = (O + M + P) / 3; PERT (beta) = (O + 4M + P) / 6 with standard deviation (P - O) / 6. Parametric needs a reliable unit rate; analogous suits early phases with little detail.
- How it shows up
- You are given optimistic, most likely and pessimistic values and asked for the PERT estimate or the range at a given confidence; or asked which technique fits repeatable work.
- Common confusion
- Mixing up the triangular and beta formulas, or treating effort hours as duration without accounting for resource availability and calendars.
2.4 Sequence activities incorporating defined dependencies, milestones and constraintsBuild logic with relationship types, lags, leads and constraints.
- What it means
- You link activities using finish-to-start, start-to-start, finish-to-finish and start-to-finish relationships, include internal, external and cross-program dependencies, and apply constraints only where justified.
- What to understand
- Every activity except the start and finish should have at least one predecessor and one successor; hard constraints such as must-finish-on override logic and can create negative float.
- How it shows up
- A question describes two activities that can overlap once the first is half done; the answer is a start-to-start relationship with a lag, not breaking the logic.
- Common confusion
- Using lags to represent work that should be an activity, or using hard date constraints where logic would drive the date correctly.
2.5 Identify critical and near-critical path(s)Use CPM, critical chain, PERT and Monte Carlo simulation.
- What it means
- You run forward and backward passes to find the longest path and float, flag near-critical paths with little float, and use probabilistic methods to see which paths are likely to drive the finish.
- What to understand
- Total float = LS - ES (or LF - EF); free float = earliest ES of successors minus the activity's EF. A near-critical path with high uncertainty can become critical, which Monte Carlo criticality indexes reveal.
- How it shows up
- A small network is given; you compute float for one activity, or decide which path to watch when two paths are close in length.
- Common confusion
- Believing the critical path is the path with the most activities or the most risk; it is the longest path through the logic.
2.6 Develop the project resource breakdown structure (RBS), determine resource availability, and assign resourcesClassify resources, confirm availability and load activities.
- What it means
- You build the RBS by resource category and type, confirm availability with calendars and managers, and assign resources and quantities to activities.
- What to understand
- Resource calendars and assignment units change durations: a 40-hour task at 50% allocation takes ten working days, not five.
- How it shows up
- A resource is assigned to two activities at once; the scenario asks what the over-allocation will do to the dates and what to do about it.
- Common confusion
- Confusing the RBS (resource types) with the OBS (organizational units) or the risk breakdown structure, which shares the acronym.
2.7 Adjust schedule model based upon resource availability, available budget, and other known constraintsLevel, smooth and compress to create a resource-constrained schedule.
- What it means
- You resolve over-allocations by leveling or smoothing, apply budget and funding limits, and use crashing or fast-tracking when constraints push the finish beyond a required date.
- What to understand
- Leveling can extend the finish and change the critical path; smoothing moves work only within float and keeps the finish. Crashing adds cost to shorten critical activities; fast-tracking overlaps them and adds risk.
- How it shows up
- After leveling, the finish moves by two weeks; you identify why and choose between accepting it, adding resources, or compressing the new critical path.
- Common confusion
- Crashing non-critical activities, which costs money without shortening the project.
2.8 Align schedule with the overall program plan or integrated master plan (IMP)Integrate project logic with program events and interfaces.
- What it means
- You trace project activities and milestones to program events, accomplishments and criteria in the integrated master plan, and link cross-project interfaces in the integrated master schedule.
- What to understand
- The IMP is event-based (what must be accomplished and by which criteria); the integrated master schedule (IMS) is the time-phased network that supports it.
- How it shows up
- A project's deliverable feeds another project; the scenario asks how to represent the interface so slippage is visible across the program.
- Common confusion
- Treating the IMP as a detailed schedule; it defines events and criteria, not durations.
2.9 Analyze major milestones against statement of work (SOW) and the contractConfirm the model meets contractual dates.
- What it means
- You compare forecast milestone dates from the logic-driven model with dates required by the SOW, contract or agreement and identify gaps before baseline.
- What to understand
- Gaps are resolved by changing the plan (logic, resources, compression) or negotiating the requirement, not by imposing a hard constraint that hides negative float.
- How it shows up
- The model forecasts a contract milestone ten days late; you choose to analyze compression options and inform the project manager rather than constrain the date.
- Common confusion
- Setting a must-finish-on constraint to match the contract, which reports compliance while the logic says otherwise.
2.10 Perform schedule risk analysis using quantitative tools or techniquesTest milestone achievability with what-if and Monte Carlo analysis.
- What it means
- You apply duration uncertainty and discrete risk events to the network and simulate many iterations to produce probability distributions for milestones and the finish date.
- What to understand
- Output is read as confidence levels (for example, P80 date), criticality indexes and sensitivity rankings; merge bias means parallel paths make the finish later than any single path suggests.
- How it shows up
- A simulation shows a 40% chance of meeting the date and the organization requires 80%; you decide whether to add schedule reserve, add responses or renegotiate.
- Common confusion
- Believing the CPM date is the most likely date. With uncertainty and merge points it is usually optimistic.
2.11 Obtain a consensus of the project customer, sponsor, project manager, and project teamAgree the schedule before it becomes the baseline.
- What it means
- You walk key stakeholders through the logic, assumptions, resource plan and risk results so they accept the schedule as the baseline.
- What to understand
- Consensus means informed agreement on dates and assumptions, including the confidence level; it is a precondition for a credible baseline.
- How it shows up
- The sponsor rejects a date without seeing its basis; the next step is to review the assumptions and risk analysis with the sponsor, not to change the date.
- Common confusion
- Treating sponsor sign-off alone as consensus while the team that must perform the work disagrees with the durations.
2.12 Establish the Performance Measurement Baseline (PMB)Integrate scope, schedule and cost into the measurement baseline.
- What it means
- You combine the approved scope, schedule baseline and time-phased budget into the PMB against which earned value performance is measured.
- What to understand
- The PMB equals the budget at completion allocated across control accounts plus undistributed budget; management reserve sits outside the PMB, and the PMB changes only through formal change control.
- How it shows up
- A question asks which reserve is part of the PMB, or what must exist before earned value reporting can begin.
- Common confusion
- Including management reserve in the PMB, or treating any schedule update as a new PMB.
High-yield concepts
The terms, rules and formulas this domain turns into questions most often.
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Forward and backward pass
The forward pass computes early start and early finish from the project start; the backward pass computes late finish and late start from the project finish.
- Remember
- On a merge, the forward pass takes the latest predecessor finish; on a burst, the backward pass takes the earliest successor start.
- Tested as
- Required for every float and critical path calculation.
- Trap
- Taking the earliest predecessor finish at a merge point, which understates the project duration.
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Total float vs. free float
Total float is how long an activity can slip without delaying the project finish; free float is how long it can slip without delaying any successor's early start.
- Remember
- TF = LS - ES; FF = min(ES of successors) - EF. Free float is never greater than total float.
- Tested as
- Common calculation and interpretation question in this domain.
- Trap
- Reporting total float when the question asks whether a successor will be affected.
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PERT estimate
Beta-weighted estimate (O + 4M + P) / 6 with standard deviation (P - O) / 6, used to express uncertainty in a duration.
- Remember
- Mean plus or minus one standard deviation covers about 68%; two covers about 95%.
- Tested as
- Direct calculation in estimating and risk questions.
- Trap
- Using (O + M + P) / 3 when the question specifies PERT or beta distribution.
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Dependency types
Mandatory (hard logic from the nature of work), discretionary (preferred logic), external (outside the project) and internal (within the project); relationships are FS, SS, FF or SF.
- Remember
- Discretionary logic is the first candidate to remove when fast-tracking.
- Tested as
- Sequencing and compression questions hinge on dependency type.
- Trap
- Trying to fast-track across a mandatory dependency, such as starting to paint before the wall exists.
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Lag vs. lead
A lag delays the successor relative to the relationship; a lead (negative lag) lets the successor start before the predecessor's relationship point.
- Remember
- Lags are waiting time with no resources; if work or resources are involved, model it as an activity.
- Tested as
- Appears in sequencing, schedule audit and fast-tracking scenarios.
- Trap
- Using a long lag to represent a curing or approval task that should be visible and statused.
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Resource leveling vs. smoothing
Leveling resolves over-allocations and may extend the finish date; smoothing evens out resource use only within available float.
- Remember
- Leveling can change the critical path; smoothing cannot change the finish.
- Tested as
- Asked whenever resources are over-allocated or a fixed finish is stated.
- Trap
- Choosing leveling when the scenario says the finish date cannot move.
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Crashing vs. fast-tracking
Crashing adds resources or cost to shorten critical activities; fast-tracking overlaps activities that were planned in sequence.
- Remember
- Crash the critical activity with the lowest cost per day saved first, and recheck the critical path after each step.
- Tested as
- Classic compression question when a contract milestone is at risk.
- Trap
- Crashing an activity with float, which costs money and saves no time.
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Monte Carlo schedule risk analysis
Repeated simulation of the network with sampled durations and risk events to produce a distribution of finish dates.
- Remember
- Read results as confidence levels such as P50 or P80 and use criticality and sensitivity indexes to find drivers.
- Tested as
- Used to judge whether milestones are achievable within risk tolerance before baselining.
- Trap
- Treating the deterministic CPM date as the expected date.
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Merge bias
When parallel paths converge, the probability of meeting the merge date is the product of each path's probability, so the merge is later than any single path suggests.
- Remember
- More parallel near-critical paths means lower confidence in the deterministic date.
- Tested as
- Explains why Monte Carlo results are later than CPM results.
- Trap
- Assuming only the critical path matters for risk.
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Critical chain buffers
Project buffer at the end of the critical chain and feeding buffers where non-critical chains join it, sized from the safety removed from estimates.
- Remember
- Buffers protect the chain; tasks are scheduled with aggressive estimates and resource dependencies.
- Tested as
- Appears in path identification questions alongside CPM.
- Trap
- Placing feeding buffers on the critical chain itself.
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Performance measurement baseline (PMB)
The integrated, time-phased scope, schedule and cost baseline used for earned value, comprising control account budgets plus undistributed budget.
- Remember
- PMB + management reserve = contract budget base; management reserve is outside the PMB.
- Tested as
- Asked in baseline establishment and reserve questions.
- Trap
- Counting management reserve as part of the PMB.
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Negative float
Float below zero, produced when a constraint or required date is earlier than the logic can achieve.
- Remember
- Negative float shows how many days must be recovered to meet the constraint.
- Tested as
- Diagnoses unmet contract milestones in planning.
- Trap
- Deleting the constraint to clear negative float instead of addressing the shortfall.
Side by side
Concepts candidates mix up, compared on the point that decides the answer.
Total float vs. free float vs. negative float
| Concept | Meaning | Key difference | Common trap |
|---|---|---|---|
| Total float | Slip allowed without delaying the project finish or a constrained date | Shared along a path | Assuming each activity on a path can use all of it independently |
| Free float | Slip allowed without delaying any successor's early start | Belongs to one activity | Using it to judge the impact on the project finish |
| Negative float | Amount by which logic misses a constraint or required date | Signals required recovery | Hiding it with a hard constraint |
Analogous vs. parametric vs. three-point vs. PERT estimating
| Concept | Meaning | Key difference | Common trap |
|---|---|---|---|
| Analogous | Duration from a similar past activity, adjusted by judgment | Fast, low accuracy, top-down | Using it when reliable unit rates exist |
| Parametric | Quantity times a statistically valid rate, for example metres per day | Accuracy depends on the rate's validity and scalability | Applying a rate outside the range it was derived from |
| Three-point (triangular) | (O + M + P) / 3 | Equal weight to all three values | Confusing it with the beta formula |
| PERT (beta) | (O + 4M + P) / 6, SD = (P - O) / 6 | Weights the most likely value four times | Forgetting to compute the standard deviation when a confidence range is asked |
Leveling vs. smoothing vs. crashing vs. fast-tracking
| Concept | Meaning | Key difference | Common trap |
|---|---|---|---|
| Resource leveling | Delay work to resolve over-allocation | May extend the finish | Using it when the finish is fixed |
| Resource smoothing | Even out demand within float | Finish stays the same; over-allocation may remain | Expecting it to remove every over-allocation |
| Crashing | Add resources or cost to shorten critical activities | Increases cost | Crashing non-critical work |
| Fast-tracking | Overlap sequential activities | Increases risk and possible rework | Overlapping across mandatory dependencies |
WBS vs. OBS vs. RBS
| Concept | Meaning | Key difference | Common trap |
|---|---|---|---|
| WBS | Deliverable-oriented decomposition of scope | Answers what work | Organizing it by department |
| OBS | Organizational units responsible for work | Answers who is accountable | Confusing it with the resource list |
| RBS (resource) | Hierarchy of resource categories and types | Answers what kind of resources | Confusing it with the risk breakdown structure |
Exam traps
Each trap is an answer that looks right. Learn the clue that should change your mind.
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Constraint to the rescue
- What candidates pick
- Apply a must-finish-on constraint so the milestone shows the contract date.
- Why it looks right
- The schedule immediately shows compliance with the contract.
- Why it's wrong
- The constraint overrides logic, produces negative float upstream and hides a real shortfall from stakeholders.
Clue to watch for The logic-driven forecast is later than the required date and the question asks for the BEST action.
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Most activities equals critical
- What candidates pick
- The path with the most activities or the riskiest work as the critical path.
- Why it looks right
- Busy or risky paths feel like they drive the project.
- Why it's wrong
- The critical path is the longest duration path through the network; activity count and risk do not define it.
Clue to watch for Sum the durations per path, including lags, before answering.
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Leveling with a fixed finish
- What candidates pick
- Resource leveling to fix an over-allocation.
- Why it looks right
- Leveling is the standard over-allocation fix.
- Why it's wrong
- Leveling may push the finish; if the date is fixed, smoothing within float, adding resources or reassigning work is required.
Clue to watch for Phrases like 'the end date cannot change' or 'contractual completion date'.
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CPM date as the promise
- What candidates pick
- Baseline the deterministic CPM finish date as the committed date.
- Why it looks right
- It is the date the tool calculates.
- Why it's wrong
- With uncertainty and merge bias the CPM date often has low probability; the baseline should reflect agreed confidence and reserve.
Clue to watch for A simulation result or confidence requirement is mentioned in the scenario.
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Effort equals duration
- What candidates pick
- A 40-hour task completes in five days for a half-time resource.
- Why it looks right
- 40 hours over 8-hour days looks like five days.
- Why it's wrong
- At 50% allocation the resource works four hours a day, so duration is ten working days.
Clue to watch for Look for allocation percentages or resource calendars in the stem.
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Lag as hidden work
- What candidates pick
- Model a ten-day inspection as a ten-day lag.
- Why it looks right
- It is quick and keeps the network tidy.
- Why it's wrong
- Lags cannot be statused or resourced; real work must be an activity so progress and resources are visible.
Clue to watch for The delay involves people, approvals or deliverables rather than pure waiting time.
Answer framework
Use this sequence when a planning question asks which step or technique comes next before baselining.
- Confirm scope is fully decomposed into work packages, each with an accountable owner inside a control account, before adding activities.
- Check that each activity has a basis of estimate and logic links, and that the estimating technique matches the data available.
- Calculate the critical and near-critical paths, then load resources and resolve over-allocations with leveling or smoothing as the date allows.
- Compare forecast milestones with contract and program dates and test achievability with schedule risk analysis at the required confidence level.
- Resolve gaps through logic, resources, compression or negotiation, then gain stakeholder consensus and set the PMB under change control.
Practice question
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Study strategy
Start with network mechanics, because they underpin a large share of this domain. Draw ten small networks by hand with mixed relationship types and lags, run forward and backward passes, and compute total and free float until it takes under three minutes each. Then add estimating: practice PERT and triangular formulas and standard deviation ranges.
Next, study resource loading and adjustment. Work examples where allocation percentages change duration, then compare leveling and smoothing on the same network and observe how the critical path can shift. Follow with compression drills: given crash costs, choose the cheapest critical activity and recheck paths after each step.
Commonly underestimated areas are the integrated master plan, control account structure and the PMB composition, which are short to learn but easy to confuse. Schedule risk analysis is another: learn to read a cumulative probability curve and explain merge bias in one sentence.
Afterwards, practice timed mixed sets where calculation and judgment questions alternate, then move to Domain 3 to see how this baseline is used for variance analysis.
FAQ
How heavily is Schedule Planning and Development weighted?
PMI weights it at 31%, second only to Schedule Monitoring and Controlling at 35%. As a planning estimate that is about 53 of 170 items.
Which formulas should I memorize for this domain?
Forward and backward pass rules, total float (LS - ES), free float (successor ES - EF), triangular (O + M + P) / 3, PERT (O + 4M + P) / 6 and its standard deviation (P - O) / 6.
Will I need to draw full network diagrams?
Expect small networks described in text or shown as a figure. Sketching each network quickly and running both passes is the reliable way to avoid logic errors.
What is the difference between leveling and smoothing?
Leveling resolves over-allocations even if the finish moves. Smoothing works only within float and keeps the finish date, so some peaks may remain.
Is critical chain tested in detail?
The ECO names critical chain among path identification techniques, so know how buffers are placed and how it differs from CPM, especially its treatment of resource dependencies.
How does this domain connect to earned value?
This domain sets the PMB that earned value measures against. Planned value comes from the time-phased baseline built here, and Domain 3 compares earned and actual values with it.
How much study time should I plan?
A planning estimate is 35 to 50 hours, with most of it spent on hands-on network and estimating practice rather than reading.
Other Project Management certifications
Where the same subject shows up in other exams. Cards marked "Same subject" open the matching domain.
- PRINCE2 7 Practitioner Study guide
- PMI Risk Management Professional Study guide
- Project Management Professional Study guide
- CompTIA Project+ Study guide
- PRINCE2 7 Foundation Study guide
- Portfolio Management Professional Study guide
- Program Management Professional Study guide
- Certified Associate in Project Management Study guide
- Agile Project Management Study guide
- PMI Agile Certified Practitioner Study guide
- Project Management Professional (PMBOK 7) Study guide
- Disciplined Agile Scrum Master Study guide
Test your Domain 2 knowledge
You have worked through decomposition, estimating, network logic, resource adjustment and schedule risk analysis. Test whether you can compute float and choose the right adjustment under time pressure.
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