Construction Management MCQ

Topic-wise practice for PSC and Engineering License Exams in Nepal — Bar Chart, Network Analysis, PERT & CPM

Bar Chart, Gantt & Milestone Chart

Bar chart is (are)

  1. A pictorial chart
  2. Two coordinate system
  3. Unable to depict interdependencies
  4. All of these
Ans. (d) All of these

Bar chart is a graphical representation of activity vs time. It is also known as Gantt chart. Introduced by Henry Gantt in 1917 AD.

Advantages:
  • It can depict the resource requirement.
  • Progress is expressed as percentage.
  • It is simple to draw and no special skill is required.
  • It is visual representation of project.
Limitations:
  • Lack of degree of details.
  • Critical activities are not shown.
  • Activity inter-relationship are not shown.

Bar charts are suitable for

  1. major projects only
  2. minor projects only
  3. medium projects only
  4. any project
Ans. (b) minor projects only

Bar charts:
  • Bar charts are suitable for minor projects only.
  • It is a graphical representation of activity v/s time.
  • It is also referred to as Gantt chart.

Various activities of a project, are shown on bar charts by:

  1. Horizontal lines
  2. Vertical lines
  3. Arrows
  4. Circles
Ans. (a) Horizontal lines

Various activities of a project are shown on the bar chart by horizontal lines. An activity bar chart, also known as Gantt chart, clearly indicates how different tasks are dependent on each other in a project. It is used in addition to the activity network diagram and enhances the efficiency of project management.

A bar chart is drawn for

  1. time versus activity
  2. activity versus resources
  3. resources versus progress
  4. progress versus time
Ans. (a) time versus activity

A bar chart is drawn for time versus activity.
  • Usually the horizontal axis represents the time duration and the vertical axis represents activities or jobs respectively.
  • The beginning and end of each bar shows the "time of start" and "time of finish" of the activity respectively.
  • The length of the bar represents the time required for the completion of that activity.

A bar chart is also known as

  1. flow chart
  2. time chart
  3. travel chart
  4. Gantt chart
Ans. (d) Gantt chart

Bar charts:
  • Bar charts are suitable for minor projects only.
  • It is a graphical representation of activity v/s time.
  • It is also referred to as Gantt chart.

Gantt chart provides information about

  1. Break even point analysis
  2. Production schedule
  3. Material handling layout
  4. Determining selling price
Ans. (b) Production schedule

Gantt chart provides information about the production schedule — it displays which tasks are scheduled, when they start and finish, and how long each takes.

The first method invented for planning projects was

  1. Bar chart method
  2. Milestone chart
  3. Critical Path Method (CPM)
  4. Programme Evaluation and Review Technique (PERT)
Ans. (a) Bar chart method

The first method invented for planning projects was the Bar chart method.
  • It was first introduced by Henry Gantt around 1900 AD.
  • It is a pictorial chart.
  • It has a two co-ordinate system — the horizontal co-ordinate represents the elapsed time and the vertical represents the job or activity performed.
  • The length of the bar shows the time of completion.
  • The beginning and end of each bar represents the starting and finishing time of a particular activity respectively.

Milestone chart is an improvement over

  1. CPM
  2. All of these
  3. PERT
  4. Bar chart
Ans. (d) Bar chart

Milestone chart is a modification over the bar chart in which the limitations of the bar chart are removed up to a certain extent.
  • A milestone chart shows the events in a chronological sequence but not in a logical sequence.
  • Within an activity, the relationship between two specific milestones is revealed by the milestone chart, whereas the relationship between and among milestones contained in different activities is not indicated.

Activity, Event & Dummy Activity

An activity of a project requires

  1. events
  2. resources
  3. time and resources
  4. equipment
Ans. (c) time and resources

An activity of a project requires time and resources.
  • A task or activity represents an identifiable unit of work that is performed by a single individual or group of workers, with a clear beginning and end.
  • For example, in constructing a house, the project is divided into tasks and sub-tasks such as making the house, electric connection, painting, etc.

Actual performance of a task is called

  1. an event
  2. an activity
  3. duration
  4. any one of these
Ans. (b) an activity

Actual performance of a task is called an activity. An activity consumes time and resources, while an event is an instantaneous point marking start or completion of an activity.

An arrow represents

  1. an event
  2. an activity
  3. a dummy activity
  4. slack
Ans. (b) an activity

An arrow represents an activity. Activity is the resource-consuming element of the project.

Each circle represents

  1. a network
  2. an event
  3. an activity
  4. critical path
Ans. (b) an event

Each circle (node) represents an event. An event is an instant of time at which some milestone of the project is achieved.

An event is:

  1. A definite time interval
  2. A dummy activity
  3. A useful criterion
  4. The start and / or finish of an activity or the group of activities
Ans. (d) The start and / or finish of an activity or the group of activities

Event – The start and finish of an activity or a group of activities is called an event.

Dummy activity – A dummy activity is intended to show a path of action in a project activity diagram and is employed when a logical relationship between two activities cannot be linked by showing the use of arrows linking one activity to another.

The occurrence of the completion of an activity, is called its

  1. Head event
  2. tail event
  3. dual role event
  4. none of these
Ans. (a) Head event

Head event: An event which marks the completion of an activity (or activities) is called head event or succeeding event. If a particular event represents the end of a project, then it is called the end event.

Tail event: An event which marks the beginning of an activity (or activities) is called tail event or preceding event. If a particular event represents the start of a project, it is called the initial event.

The activity which comes immediately before other activity is called as?

  1. Float
  2. Milestone
  3. Predecessor
  4. Successor
Ans. (c) Predecessor

  • Predecessor – controls the start or finish of another activity.
  • Successor – depends on the start or finish of another activity.

The two basic elements used in a network, are _______.

  1. Activity and Event
  2. Activity and time
  3. Time and Event
  4. Activity and path
Ans. (a) Activity and Event

The two basic elements used in a network are activity and event.
  • CPM is an activity-oriented technique, which means the network is constructed on the basis of activities. It is used for repetitive type of work and has a deterministic approach.
  • PERT is an event-oriented technique.

A dummy activity is represented by

  1. full line
  2. dotted line
  3. parallel double full line
  4. perpendicular full line
Ans. (b) dotted line

A dummy activity is an artificial activity represented by dashed/dotted arrows which neither consumes any time nor any resources. A dummy job takes zero time to perform because it is used solely to illustrate the precedence relationship between activities.

Dummy activities are used to

  1. determine the critical path
  2. determine the project completion time
  3. maintain the required network
  4. None of the above
Ans. (c) maintain the required network

Dummy activity is an artificial activity represented by dashed arrows which neither consumes any time nor any resources. It is used solely to maintain the correct logic and precedence relationship of the network.

Which of the following is a dummy activity

  1. excavation of the foundations
  2. await the arrival of concrete material
  3. both (a) and (b)
  4. none of these
Ans. (b) await the arrival of concrete material

"Await the arrival of concrete material" is a dummy activity, as it consumes no resources. "Excavation of the foundations" is a real activity because it consumes both time and resources.

PERT Analysis

In PERT analysis, the time estimate of activities follows–

  1. Normal distribution curve
  2. β-distribution curve
  3. Poisson's distribution curve
  4. Binomial distribution curve
Ans. (b) β-distribution curve

PERT –
  • It is a probabilistic approach of solving technique.
  • Event oriented
  • It has three time estimates (optimistic, most likely, pessimistic)
  • The time estimate of activity follows β-distribution curve.
  • Used in R & D projects
  • Concept of slack is represented in PERT
  • In PERT critical path by joining critical events is represented.

PERT is

  1. Activity oriented
  2. Event oriented
  3. Time oriented
  4. Resources oriented
Ans. (b) Event oriented

Programme Evaluation and Review Technique (PERT) is event oriented. In PERT analysis–
  • An event is either the start or completion of an activity.
  • An event represents a noteworthy, significant and recognizable point in the project.
  • Event acts as control points in a project.
  • An event is an accomplishment occurring at an instantaneous point in time, but requiring no time or resources itself.

In PERT analysis, the duration of the activities is taken as

  1. optimistic time
  2. pessimistic time
  3. most likely time
  4. expected mean time
Ans. (d) expected mean time

In PERT analysis, the duration of the activities is taken as expected mean time ( te = (to + 4tm + tp)/6 ), where to = optimistic time, tm = most likely time, tp = pessimistic time.

Critical Path, Float & Slack

The critical path consists of

  1. the longest sequence of activities from project start to finish
  2. the sequence of the most important activities
  3. the sequence of the activities susceptible for highest risk
  4. the sequence of the activities having the maximum expenditures
Ans. (a) the longest sequence of activities from project start to finish

The critical path consists of the longest sequence of activities from project start to finish. It determines the minimum possible duration of the project.

Critical path

  1. is always longest
  2. is always shortest
  3. may be longest
  4. may be shortest
Ans. (a) is always longest

Critical path activities are the project tasks that must start and finish on time to ensure that the project ends on schedule. The critical path is always the longest path through the network.

The critical activity has:

  1. Maximum float
  2. Minimum float
  3. Negative float
  4. Zero float
Ans. (d) Zero float

Critical activity is the activity which has zero float or zero slack. Any delay in a critical activity directly delays the project completion.

When the times of earliest finish and the latest finish are equal in an operation, the operation is called

  1. critical
  2. float
  3. free float
  4. all the above
Ans. (a) critical

When the earliest finish time and the latest finish time are equal in an operation, the operation is called critical — it has zero float.

Float is

  1. the earliest time by which an activity may commence
  2. latest time by which an activity can be delayed without hampering the completion of project
  3. difference of latest allowable time and earliest expected time
  4. difference of time available and time required for an activity
Ans. (b) latest time by which an activity can be delayed without hampering the completion of project

Float is associated with an activity, whereas slack is associated with an event.

Activity having negative float is called

  1. critical activity
  2. supercritical activity
  3. sub critical activity
  4. all of the above
Ans. (b) supercritical activity

A supercritical activity is a critical activity that has negative float — meaning it is now behind schedule and needs to be finished immediately.

Positive float for any activity means that the activity is

  1. supercritical
  2. sub-critical
  3. critical
  4. none of the above
Ans. (b) sub-critical

Positive float for any activity means that the activity is sub-critical — it has spare time available and can be delayed without delaying the project.

Quick summary:
  • Float greater than 0 means sub-critical activity
  • Float equal to 0 means critical activity
  • Float less than 0 means supercritical activity

Slack time refers to

  1. an activity
  2. an event
  3. both event and activity
  4. none of the above
Ans. (b) an event

Slack is the time by which the occurrence of an event can be delayed without affecting the scheduled completion time of the project. Slack time refers to an event.

S (slack) = TL – TE

where TL = Latest allowable occurrence time and TE = Earliest expected event occurrence time.

Slack is the difference between the earliest finish time and ...... of any event.

  1. latest starting time
  2. earliest starting time
  3. latest finish time
  4. total float
Ans. (c) latest finish time

Slack is the time by which the occurrence of an event can be delayed without affecting the scheduled completion time of the project.

S (slack) = TL – TE

where TL = Latest allowable occurrence time and TE = Earliest expected event occurrence time.

Slack of any event is the difference between

  1. Free Float & Independent Float
  2. Earliest Finish Time & Latest Finish Time
  3. Earliest Starting Time & Latest Finish Time
  4. Earliest Finish Time & Latest Starting Time
Ans. (b) Earliest Finish Time & Latest Finish Time

Slack (or slack time) of any event is defined as the difference between the latest allowable time and the earliest expected time of the event.