Question 1

Statistics for engineers: Which statements about frequency distribution curves are correct?

Accepted Answer

Introduction / Context: Understanding shapes of frequency distribution curves helps engineers interpret data from quality control, productivity studies, and risk assessments. Key descriptors include modality, symmetry, and skewness. Given Data / Assumptions: Frequency distributions plotted as smooth curves or histograms. Basic statistical terminology: mode, normality, and skewness. No numerical calculation is required—only conceptual recognition. Concept / Approach: Unimodal distributions show a single mode (peak). A perfectly symmetric, bell-shaped curve is the normal distribution. Asymmetry in the tail (longer tail on one side) indicates skewness—positive (right) or negative (left) skew. Step-by-Step Solution: Option A: A single peak implies one mode; unimodal is correct.Option B: Symmetry around the mean defines the normal curve; correct.Option C: Departure from symmetry is skewness; correct.Therefore, all statements are correct and the comprehensive answer is 'all the above.' Verification / Alternative check: Plotting sample data (e.g., concrete strength results) often shows near-normal distributions; process shifts can create skewed patterns, validating the definitions. Why Other Options Are Wrong: None of these: Incorrect because each statement is standard statistical terminology. Common Pitfalls: Confusing multimodal with skewed; assuming real-world data are perfectly normal—tolerances and processes commonly induce skew. Final Answer: all the above.

Question 2

Project lifecycle – first stage: In the lifecycle of a construction project, which is typically the very first stage?

Accepted Answer

Introduction / Context: Every construction project follows a lifecycle from conception to closeout. Identifying the true starting point clarifies responsibility, approvals, and subsequent technical work. Given Data / Assumptions: Standard public works or private development process. Stages include proposal, feasibility, surveys, design, estimating, tendering, and execution. Administrative approvals are needed before committing resources. Concept / Approach: The first stage is the initiation of proposal—recognition of need and intent to undertake the project. Only after this are surveys commissioned, designs prepared, and estimates compiled. Step-by-Step Solution: Formulate the need (problem/opportunity) and initiate the proposal.Obtain in-principle approval to proceed to reconnaissance and surveys.Develop preliminary designs and estimates to build a business case.Invite tenders only after scope and funding are defined. Verification / Alternative check: Project management frameworks (e.g., initiation–planning–execution–monitoring–closeout) list initiation as the first phase, preceding planning activities like surveys and estimating. Why Other Options Are Wrong: Estimate, survey, tender, and funding allocation occur after initiation sets objectives and authorizes planning work. Common Pitfalls: Jumping to cost estimates or tenders without a defined problem statement and authorization leads to rework and procurement delays. Final Answer: initiation of proposal

Question 3

PERT vs. CPM orientation: Which statement correctly distinguishes the orientation of PERT and CPM techniques?

Accepted Answer

Introduction / Context: PERT and CPM are classic network-based planning tools. Understanding their focus helps practitioners select the right tool for uncertain R&D-type projects vs. repetitive construction with known activity durations. Given Data / Assumptions: PERT uses probabilistic time estimates and focuses on events (milestones). CPM uses deterministic durations and focuses on activities and their costs. Both depict logic but differ in emphasis and data requirements. Concept / Approach: PERT charts were historically 'event-oriented,' indexing nodes as events and computing expected times using optimistic, most likely, and pessimistic estimates. CPM, developed for construction/maintenance, is activity-oriented with cost–time trade-off (crashing) emphasis. Step-by-Step Solution: Identify PERT: events (nodes) mark the completion of preceding activities; uncertainty modeled with beta assumptions.Identify CPM: activities (arrows/bars) with deterministic durations; cost-curves enable crashing.Therefore, the correct distinguishing statement is that PERT is event-oriented. Verification / Alternative check: Most textbooks contrast Activity-on-Arrow PERT diagrams (event emphasis) with Activity-on-Node CPM diagrams (activity emphasis), even though modern software often uses AON for both. Why Other Options Are Wrong: Options B, C, and D contradict standard definitions. Option E is incorrect: CPM includes cost optimization; PERT focuses on time under uncertainty, not cost. Common Pitfalls: Assuming PERT and CPM are interchangeable; ignoring that risk buffers and three-time estimates are central to PERT but not CPM. Final Answer: Programme Evaluation and Review Technique (PERT) is event-oriented

Question 4

PERT time estimates: In PERT, optimistic, pessimistic, most likely, and expected time estimates refer to what?

Accepted Answer

Introduction / Context: PERT quantifies schedule uncertainty by describing each activity with three time estimates and combining them into an expected value. This approach is useful when historical data are limited or the work is novel. Given Data / Assumptions: For each activity: optimistic (a), most likely (m), pessimistic (b) durations are assessed. Expected time te is computed using a weighted average. Variance helps assess schedule risk along paths. Concept / Approach: PERT uses the relation te = (a + 4m + b) / 6 and variance sigma^2 = ((b - a) / 6)^2 for each activity, assuming a beta-like distribution. These estimates belong to activities, not events. Step-by-Step Solution: Define optimistic time (a): minimum plausible duration if everything goes well.Define pessimistic time (b): maximum plausible duration under adverse conditions.Define most likely time (m): modal estimate under normal conditions.Compute expected time (te) for scheduling and risk analysis. Verification / Alternative check: Summing expected times along the critical path yields the expected project duration; combining variances gives an estimate of completion probability. Why Other Options Are Wrong: Each individual option is correct; therefore the only comprehensive choice is 'All the above.' Common Pitfalls: Applying PERT formulas to events; confusing deterministic CPM durations with PERT probabilistic estimates; ignoring variance when communicating schedule risk. Final Answer: All the above.

Question 5

CPM network times: Which statements are correct regarding earliest and latest times for activities and events in CPM?

Accepted Answer

Introduction / Context: Forward and backward pass calculations in CPM determine schedule flexibility (float) and the critical path. Understanding the definitions of ES, EF, LS, and LF is essential for correct computations. Given Data / Assumptions: Activity-on-Arrow or Activity-on-Node representation with consistent logic. Deterministic durations are given. No resource constraints are applied during time analysis. Concept / Approach: Forward pass yields earliest event times and thus ES/EF; backward pass yields latest allowable times without delaying project finish, thus LS/LF. Float metrics derive from these times. Step-by-Step Solution: ES of an activity equals the earliest time its start node occurs.EF = ES + duration.LF equals the latest allowable time of its finish node.LS = LF - duration.Zero float means EF = LF and ES = LS on critical activities. Verification / Alternative check: Check consistency: EF of predecessors must be less than or equal to ES of successors. Any violation indicates a logic or calculation error. Why Other Options Are Wrong: Each statement accurately defines schedule times; hence 'All the above' is correct. Common Pitfalls: Mixing event times with activity times; neglecting multiple predecessors by not taking the maximum EF when computing successor ES. Final Answer: All the above.

Question 6

Float concepts in CPM: Which of the following statements about total float, free float, independent float, and interfering float are correct?

Accepted Answer

Introduction / Context: Float (slack) quantifies schedule flexibility. Proper use of float helps level resources and absorb uncertainties without delaying project completion. Different float types serve different management purposes. Given Data / Assumptions: Total float TF = LS − ES = LF − EF. Free float FF = min(ES of successors) − EF. Independent float IF = max(0, ES of activity − LF of predecessor − duration). Interfering float = TF − FF. Concept / Approach: Total float measures how much an activity may move without affecting project finish; free float preserves successors; independent float is the portion independent of both predecessors and successors; interfering float is the portion that, if used, will delay the early start of successors but not the project finish. Step-by-Step Solution: Confirm total float via ES/LS or EF/LF relations.Compute free float using successor earliest starts.Compute independent float using predecessor latest finishes and own ES.Find interfering float as the difference: TF − FF. Verification / Alternative check: Network calculations should show TF ≥ FF ≥ 0 and IF ≥ 0 (by definition floored at zero). Critical activities have TF = FF = IF = 0. Why Other Options Are Wrong: All listed statements align with standard CPM definitions; therefore 'All the above' is correct. Common Pitfalls: Using free float where preserving successor early start is not required; double-counting float when multiple successors exist; forgetting that independent float can be zero even when total float is positive. Final Answer: All the above.

Question 7

The three time estimates for the activities of the network shown in the given figure are shown above their arrows. The earliest expected time for the event 4, is

Accepted Answer

19

Question 8

Project scheduling notation in PERT/CPM Which of the following statements about standard time notations and obligations in network planning is correct?

Accepted Answer

Introduction / Context: Pertinent exam questions on PERT/CPM test whether you recognize standard symbols and how contractual deadlines are incorporated into the network. Knowing these conventions ensures you can run forward and backward passes correctly and interpret float values. Given Data / Assumptions: TE stands for earliest event occurrence time found from the forward pass. TL stands for latest event occurrence time found from the backward pass. Ts is frequently used to denote specified or contractual completion time for the project. At the terminal event, TL is fixed to the contractual time to seed the backward pass. Concept / Approach: In a forward pass, you add activity durations to find each event’s earliest occurrence time, TE. In the backward pass, you propagate constraints from the required completion time backwards to get TL values. If a contract specifies a finish time Ts, you set TL at the last event equal to Ts and compute other TL values from there. Step-by-Step Solution: Confirm the notation: TE = earliest occurrence time; TL = latest occurrence time; Ts = specified finish time.Recognize that the backward pass needs a finishing boundary condition: TL at the terminal event equals Ts.Therefore all four statements correctly describe standard practice. Verification / Alternative check: Check a simple network: fixing TL at the end to Ts ensures that float values reflect the contract, not just a theoretical schedule with no deadline. Why Other Options Are Wrong: Each individual statement (a–d) is true; choosing only one would ignore the rest of the correct conventions. Hence the aggregated choice is most accurate. Common Pitfalls: Confusing activity times with event times; forgetting to anchor the backward pass to the contractual completion time leads to incorrect floats. Final Answer: All the above

Question 9

PERT basics – what is PERT and how is it characterized? Choose the most complete description of the Program Evaluation and Review Technique (PERT).

Accepted Answer

Introduction / Context: PERT (Program Evaluation and Review Technique) is a foundational project management tool that models uncertainty in activity durations. Exams often ask for its key characteristics to distinguish it from CPM (Critical Path Method). Given Data / Assumptions: PERT treats activities between events and represents networks as event-oriented diagrams. Activities have probabilistic durations captured by three estimates. PERT saw early adoption in complex R&D projects where uncertainty is high. Concept / Approach: PERT uses three duration estimates—optimistic (to), most likely (tm), and pessimistic (tp)—to compute an expected time te and variance for each activity, supporting schedule risk assessment and probability of meeting deadlines. Step-by-Step Solution: Identify the core: event-oriented network focusing on uncertainty.Recognize the three-time-estimate model: te = (to + 4*tm + tp) / 6.Recall its classic application context: R&D and innovative projects.Hence, every statement (a–d) correctly describes PERT → choose 'All the above'. Verification / Alternative check: Compare PERT to CPM: CPM uses deterministic durations and cost–time tradeoffs; PERT emphasizes stochastic times and event orientation. Why Other Options Are Wrong: Picking only one feature under-represents PERT; the method includes all listed attributes. Common Pitfalls: Confusing activity-on-node vs event-on-node conventions; PERT historically used event-oriented representation, though modern tools also allow activity-on-node with PERT estimates. Final Answer: All the above

Question 10

A goiden rule for the procurement of construction stones, suggests

Accepted Answer

67% at the site and 33% under procurement

Question 11

Events vs activities in network planning Which of the following best represents an event (i.e., a zero-duration milestone state) rather than an activity?

Accepted Answer

Introduction / Context: In PERT/CPM networks, an activity consumes time and resources, while an event (milestone) is an instant in time marking the start or completion of one or more activities. Distinguishing between them is crucial for correct modeling. Given Data / Assumptions: Activities like fixing doors or plastering require time. Events capture states achieved, such as 'concrete cured' once curing duration is complete. Concept / Approach: Represent actions requiring time as activities; represent achieved conditions with zero duration as events. The event symbolizes completion of predecessor activities and the readiness to start successors. Step-by-Step Solution: Identify time-consuming tasks: fixing doors, plastering, and site selection are activities.Identify a milestone/condition: 'concrete cured' is a state that is attained at an instant (after curing time has elapsed).Therefore, 'Concrete cured' is the event. Verification / Alternative check: Draw a small network: an activity 'Cure concrete' precedes an event 'Concrete cured'; successors (e.g., load testing) can start from that event. Why Other Options Are Wrong: They describe activities (doing work) rather than milestone states; each has non-zero duration and resource usage. Common Pitfalls: Labeling actions as events; remember that events are zero duration checkpoints while tasks are modeled as activities. Final Answer: Concrete cured

Question 12

Who can be a contractor for executing a project? Identify the most inclusive description of a contractor involved in project execution.

Accepted Answer

Introduction / Context: Public works and private construction procurements define 'contractor' broadly, since different legal forms may undertake contractual responsibilities—sole proprietors, partnerships, companies, or public sector agencies. Given Data / Assumptions: The procurement framework allows multiple legal entities to bid and execute works. Qualification is based on capability, compliance, and experience, not just legal form. Concept / Approach: A contractor is the party that enters into a contract to deliver the works. This can be an individual (person), a registered firm or company, or even a government/para-statal agency depending on the procurement rules. Step-by-Step Solution: Recognize that eligibility focuses on capacity and compliance.A person, firm, or agency can meet the criteria.Therefore the most inclusive and correct choice is 'All the above'. Verification / Alternative check: Standard bidding documents and manuals list various acceptable legal constitutions for contractors and joint ventures. Why Other Options Are Wrong: Each single option is too narrow; the definition of contractor is not limited to one legal form. Common Pitfalls: Assuming only companies or only individuals can be contractors; procurement law usually permits several entity types subject to qualification. Final Answer: All the above

Question 13

Final selection of a construction site – who decides? In standard public works practice, which stakeholders collectively lead to the final selection of a construction site?

Accepted Answer

Introduction / Context: Site selection for public infrastructure is a multidimensional decision. Beyond technical suitability, it must satisfy planning permissions, serviceability for users, and administrative approvals. Given Data / Assumptions: Multiple stakeholders influence the final decision. Compliance with planning and regulatory bodies is mandatory. Engineering feasibility and user needs are key inputs. Concept / Approach: Successful site selection is an approval chain outcome. Departments or end users define functional needs; engineering authorities validate technical criteria; local bodies ensure statutory compliance; administrative heads grant formal sanction. Step-by-Step Solution: Identify each role: user need, engineering feasibility, statutory permission, administrative approval.Confirm that omitting any stakeholder risks delay or non-compliance.Hence, all listed parties contribute to final selection. Verification / Alternative check: Typical project preparation manuals require NOCs/permissions and technical vetting prior to administrative approval, confirming the multi-stakeholder process. Why Other Options Are Wrong: Choosing a single stakeholder oversimplifies the approval workflow; real projects need coordinated agreements. Common Pitfalls: Assuming the engineer alone or the user alone decides; approvals usually require consensus and formal clearances. Final Answer: All the above

Question 14

Floats in network analysis – identify the incorrect statement Which of the following statements about total float and free float is incorrect?

Accepted Answer

Introduction / Context: Understanding float types is essential to manage schedule flexibility. Total float indicates how long an activity may be delayed without affecting the project completion, while free float indicates how long it may be delayed without affecting the earliest start of any successor. Given Data / Assumptions: EST, EFT denote earliest start and finish; LST, LFT denote latest start and finish. Activity duration is denoted by d. Concept / Approach: Key formulas in conventional notation are: Total float TF = LFT - EFT = LST - EST = (LFT - EST) - d. Maximum time available for the activity = LFT - EST. Free float FF = min(EST of successors) - EFT (for a single successor, FF = ESTsuccessor - EFT). Step-by-Step Solution: Check (a): LFT - EST indeed represents the maximum span available; correct.Check (b): (LFT - EST) - d equals TF; correct.Check (c): LST - EST equals TF; correct.Check (d): Free float is computed as EST of successor minus EFT of the activity; the statement matches this relationship; correct.Therefore no statement is incorrect → choose 'None of these'. Verification / Alternative check: Create a small two-activity chain: A (d=4) → B; let EST(A)=0, EFT(A)=4, EST(B)=6, LFT(A)=10. Then TF(A) = 10 - 4 = 6, also LST - EST = 6, and FF(A) = 6 - 4 = 2, validating the formulas. Why Other Options Are Wrong: Options (a)–(d) are correct statements; only picking one as 'incorrect' would contradict standard definitions. Common Pitfalls: Mixing up EST/EFT with LST/LFT; forgetting to subtract duration when moving from 'maximum available time' to total float. Final Answer: None of these

Question 15

For the network shown in the given figure, the expected time for the activity

Accepted Answer

Expected time = (Pessimistic value + 4*most likely value + Optimistic value)/6. 1-2 is 4. 2-3 is 7. 3-4 is 8.

Question 16

Optimistic time, most likely time and pessimistic times for the activities of a network in the given figure are written above their arrows. If the contractual obligation time for the project is 75, the latest occurrence time for the event 2, is

Accepted Answer

25

Question 17

Classification in construction management: How are residential buildings generally categorized? In construction planning and estimation, residential buildings (houses, apartments, hostels) are typically treated as which class of construction based o…

Accepted Answer

Introduction / Context: Construction projects are often grouped by their scale, complexity, and typical loads on structures and foundations. This categorization helps planners estimate resources, time, equipment, and risk. Residential buildings—such as houses and apartment blocks—are commonly placed in the light-construction category due to relatively smaller spans, lighter equipment, and less complex plant and process work compared with heavy civil or industrial jobs. Given Data / Assumptions: Residential buildings are typical dwellings or hostels rather than industrial facilities. They generally use smaller cranes or no cranes, standard concreting methods, and moderate logistics. Comparison classes include heavy construction (dams, bridges, tunnels) and industrial construction (plants, refineries, powerhouses). Concept / Approach: Light construction implies moderate structural systems, modest foundation demands, and straightforward services. Heavy construction is defined by massive earthworks, deep foundations, and large-scale machinery. Industrial construction emphasises process integration, specialized equipment, and stringent services coordination. Residential work fits light construction best in terms of typical loadings, logistics, and equipment needs. Step-by-Step Solution: Classify by scale: Residential buildings rarely require heavy plant or specialized process lines.Consider structural loads: Standard live loads and spans are modest compared with bridges or power plants.Map to category: These attributes align with “light construction.” Verification / Alternative check: Project management texts and estimation manuals routinely treat residential building works as light construction for scheduling norms, productivity rates, and equipment selection baselines. Why Other Options Are Wrong: Heavy construction: Better suited to dams, harbours, metros, or long-span bridges.Industrial construction: Reserved for factories, refineries, power plants with process systems.Private construction: A funding/ownership term, not a technical class. Common Pitfalls: Confusing ownership (public vs private) with technical class (light/heavy/industrial). Assuming a large residential complex is “heavy”; despite size, its nature remains light compared with industrial or mega civil works. Final Answer: light construction

Question 18

Project classification: Railway projects are treated as what type of construction? In civil engineering project management, how are railway projects (permanent way, yards, bridges, station works) typically categorized based on scale and resource int…

Accepted Answer

Introduction / Context: Railway projects involve track formation, bridges, tunnels, yards, signalling, and large-scale earthwork. These features demand heavy plant, long construction corridors, and complex logistics. In standard classifications, such undertakings fall under heavy construction due to their magnitude and specialized equipment requirements. Given Data / Assumptions: Railway projects include track bed formation, ballast, sleepers, rail laying, structures, and systems. Large quantities of earthwork and concrete are typically involved. Coordination across long linear alignments and multiple disciplines is needed. Concept / Approach: Heavy construction is characterised by high material volumes, specialized equipment (tampers, track-laying machines, piling rigs), and demanding site logistics. Railways fit this definition, whereas light construction applies to small buildings and industrial construction to process plants. Step-by-Step Solution: Identify project nature: long linear works and major structures.Assess resource intensity: heavy plant and large crews required.Map to category: Railway projects are “heavy construction.” Verification / Alternative check: Standard textbooks in project planning and estimation consistently list railways with highways, dams, and canals as examples of heavy construction. Why Other Options Are Wrong: Light construction: Suits residential or small commercial works.Industrial construction: Reserved for factories/power plants focused on process systems.None of these: Incorrect because a clear category exists. Common Pitfalls: Confusing funding or operation (public utility) with project classification. Underestimating the engineering intensity of rail corridors compared to buildings. Final Answer: heavy construction

Question 19

PERT/CPM notation: How is an event represented on a network diagram? In activity-on-arrow (AOA) or activity-on-node (AON) conventions, the event (milestone) is indicated by a number enclosed in which geometric shape?

Accepted Answer

Introduction / Context: Network diagrams used in PERT/CPM display the logical sequence of project activities. An “event” or “milestone” denotes the instant when an activity begins or ends. Conventions were established to represent these clearly for calculations of earliest and latest event times. Given Data / Assumptions: Classic activity-on-arrow (AOA) representation is considered. Events are zero-duration points defining the start or finish of activities. Standard drafting symbols are used to avoid ambiguity. Concept / Approach: In AOA, activities are arrows; nodes represent events. Historically, events are drawn as circles containing the event number. This aids clarity during forward (earliest event time) and backward (latest event time) passes. While AON uses boxes for activities, event circles remain standard for milestone depiction in AOA. Step-by-Step Solution: Establish that we are identifying the symbol for an event node.Recall the standard drafting practice: event number inside a circle.Select “a circle” to match conventional PERT/CPM notation. Verification / Alternative check: Common PERT/CPM references depict events as numbered circles (nodes) with connecting arrows as activities, confirming the chosen symbol. Why Other Options Are Wrong: Square, triangle, ellipse: Not the conventional AOA event symbol; could denote other diagrammatic elements but not the event node.All the above: Incorrect because a single standard shape is used. Common Pitfalls: Mixing AON (boxes for activities) with AOA event symbols. Using inconsistent symbols that hinder team interpretation. Final Answer: a circle

Question 20

Float characteristics on the critical path In Critical Path Method (CPM), a critical activity’s float value is equal to what?

Accepted Answer

Introduction / Context: Float (or slack) measures scheduling flexibility. Activities lying on the critical path control the project duration; any delay on these activities delays the entire project. Understanding float helps managers prioritise resources and monitor risks effectively. Given Data / Assumptions: CPM network with defined earliest and latest event/activity times. Critical path is the sequence with the longest total duration. Critical activities are those with no scheduling leeway. Concept / Approach: Total float = latest finish minus earliest finish (or latest start minus earliest start). For a critical activity, earliest and latest times coincide, so float = 0. This reflects that the activity must start/finish exactly as planned to avoid impacting project completion. Step-by-Step Solution: Recognize that critical path length equals project duration.On critical activities, earliest and latest times are equal.Therefore, float = 0 for every critical activity. Verification / Alternative check: Forward/backward pass computations in any CPM example will show float values zero on the identified critical path, confirming the rule. Why Other Options Are Wrong: Maximum/Minimum float: Critical activities have no leeway; the float cannot be positive.None of these: Incorrect because the correct value is exactly zero. Common Pitfalls: Confusing “near-critical” (very low float) with “critical.” Assuming float exists because of resource levelling; CPM float is purely time-based between earliest and latest values. Final Answer: zero float

Construction Management Questions