hardMultiple Select
Project Constraints: The Triple Constraint in PMBOK
Which THREE of the following are commonly recognized project constraints according to the Project Management Body of Knowledge (PMBOK)?
Quick Answer
The answer is time, cost, and scope. These three elements form the classic triple constraint in the PMBOK Guide, which states that any change to one constraint will inevitably impact at least one of the other two. For the CompTIA Project+ PK0-005 exam, this concept tests your understanding of how project constraints interact to define project success, often appearing in scenario-based questions where you must identify which constraint is most affected by a given change. A common trap is confusing quality or resources as a primary constraint, but PMBOK specifically recognizes scope, time, and cost as the core triple constraint. To remember this, think of the mnemonic "S-T-C" for Scope, Time, Cost—or simply recall that every project must answer "What will we do, how long will it take, and how much will it cost?"
⚠ Common exam trap
CompTIA often tests the distinction between project constraints (scope, time, cost) and knowledge areas (e.g., communication, risk, quality), leading candidates to mistakenly select communication or quality as primary constraints.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Cost
The PMBOK Guide identifies the classic triple constraint (also called the iron triangle) as Cost, Scope, and Time, which are the three fundamental project constraints that must be balanced against each other. Option A (Cost) is correct because the approved budget is a primary constraint that limits what resources a project can use. Option C (Scope) is correct because the defined deliverables and boundaries of the project constrain what work must be performed. Option E (Time) is correct because the schedule or deadline constrains how long the project has to deliver its scope. Options B (Communication) and D (Quality) are not part of the classic triple constraint; while both are important project management knowledge areas and can be affected by the triple constraint, they are not themselves the three commonly recognized constraints in the PMBOK framework.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Cost
Why this is correct
Cost is one of the PMBOK triple constraints, governing the approved budget within which the project must deliver its scope and schedule. It satisfies the recognised-constraint requirement because balancing cost against scope and time drives trade-off decisions throughout planning and execution.
- ✗
Communication
Why it's wrong here
Communication is a project management knowledge area and plan, not one of PMBOK's recognised constraints; the three are scope, schedule, and cost. It is tempting because communication breakdowns frequently threaten delivery, but PMBOK classifies communication under its own knowledge area rather than as a constraint.
- ✓
Scope
Why this is correct
Scope defines the work included and excluded, forming one of the PMBOK triple constraints alongside cost and time. It satisfies the recognised-constraint requirement because uncontrolled scope changes directly affect budget and schedule, requiring integrated change control.
- ✗
Quality
Why it's wrong here
Quality is a performance objective and deliverable attribute, not one of PMBOK's recognised constraints; the classic triple constraint comprises scope, schedule, and cost, with risk, resources, and quality treated separately. It is tempting because poor quality constrains acceptance, but PMBOK does not list it among the three named constraints.
- ✓
Time
Why this is correct
Time is the schedule constraint within the PMBOK triple constraints, limiting the deadline by which scope must be delivered. It satisfies the recognised-constraint requirement because compressing time typically increases cost or reduces scope, forcing explicit trade-offs.
Go deeper
Related to this question
About these practice questions
Courseiva writes every PK0-005 question from scratch — 954 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on PK0-005
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Which TWO of the following are commonly considered as project constraints according to the Project Management Body of Knowledge?
medium- A.Communication
- B.Quality
- C.Resources
- ✓ D.Scope
- ✓ E.Budget
Why D: In PMBOK terms, the classic triple constraint (also called the iron triangle) consists of scope, schedule, and cost/budget, so option D (Scope) and option E (Budget) are correct because they define the boundaries within which a project must deliver its product, service, or result. Scope represents the agreed work and deliverables, while budget represents the approved funding or cost baseline; changes to either directly affect the other constraints and require integrated change control. Option A (Communication) is a knowledge area and performance domain, not a core project constraint, and option B (Quality) is a performance objective affected by the constraints rather than one of the fundamental triple-constraint elements. Option C (Resources) can act as a limiting factor in practice, but PMBOK's commonly cited project constraints are scope, time, and cost, with quality and risk often discussed as extensions rather than the two answers sought here.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This PK0-005 practice question is part of Courseiva's free CompTIA certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PK0-005 exam.