Network analysis - directed networks, max-flow min-cut theorem, CPM, PERT, probabilistic network analysis - One Line Questions
1.
What is the formula for calculating the 'expected time' (t_e) of an activity in PERT? —
(t_o + 4*t_m + t_p) / 6
2.
What is the formula for calculating the 'variance' (σ²) of an activity in PERT? —
((t_p - t_o) / 6)²
3.
If an activity has an ES of 5, an EF of 12, an LS of 7, and an LF of 14, what is its slack? —
2 days
4.
What is the variance of an activity in PERT if t_o=4, t_m=7, and t_p=16? —
1.44
5.
In PERT, if the expected time (t_e) for an activity is 10 days, optimistic time (t_o) is 6 days, and pessimistic time (t_p) is 18 days, what is the most likely time (t_m)? —
9 days
6.
In network analysis, what does a directed edge typically represent? —
A dependency between tasks
7.
In the context of max-flow min-cut, what is a 'sink' node? —
A node where flow terminates.
8.
In the context of max-flow min-cut, what is a 'source' node? —
A node where flow originates.
9.
In network analysis, what does a 'cut' refer to? —
A set of edges whose removal disconnects the source from the sink.
10.
What is an 'activity' in the context of CPM and PERT? —
A task or operation that consumes time and resources.
11.
What is an 'event' in the context of CPM and PERT? —
A point in time marking the start or completion of an activity.
12.
Which of the following is an activity on an arrow (AOA) representation in network diagrams? —
Activities are represented by arrows.
13.
Which of the following is a representation of dependencies between tasks where activities can have multiple predecessors and successors, and different types of relationships (FS, SS, FF, SF)? —
Precedence Diagramming Method (PDM)
14.
A network diagram where activities are represented by nodes and events by arrows is known as: —
Precedence Diagramming Method (PDM)
15.
What does 'probabilistic network analysis' imply? —
Some network parameters, like activity durations, involve uncertainty and are modeled using probability distributions.
16.
In a PERT network, if the project's expected completion time is 50 days and its standard deviation is 5 days, what is the probability of completing the project within 55 days? —
Approximately 84.1%
17.
What is the probability of completing a project by a certain date in PERT analysis based on the normal distribution? —
Calculated using the Z-score derived from the expected project duration and the target date.
18.
Which theorem establishes a direct relationship between the maximum flow and the minimum cut in a flow network? —
Max-Flow Min-Cut Theorem
19.
The concept of 'cut' in a flow network is analogous to which project management concept? —
Bottleneck
20.
What does CPM stand for in project management? —
Critical Path Method
21.
Which of the following is a probabilistic approach to network analysis? —
Program Evaluation and Review Technique (PERT)
22.
The Earliest Finish Time (EF) of an activity is calculated as: —
ES + Duration
23.
What does 'EF' stand for in CPM/PERT calculations? —
Earliest Finish Time
24.
What does 'ES' stand for in CPM/PERT calculations? —
Earliest Start Time
25.
Which of the following is NOT an activity on a node (AON) representation in network diagrams? —
Activities are represented by arrows.
26.
In the context of flow networks, the 'cut capacity' is the sum of capacities of edges that: —
Go from the source side of the cut to the sink side.
27.
What is the primary limitation of the basic CPM technique? —
It assumes deterministic activity durations.
28.
What does 'LF' stand for in CPM/PERT calculations? —
Latest Finish Time
29.
What does 'LS' stand for in CPM/PERT calculations? —
Latest Start Time
30.
The Latest Start Time (LS) of an activity is calculated as: —
LF - Duration
31.
Which technique is primarily used for project scheduling and management that focuses on identifying the critical path? —
Critical Path Method (CPM)
32.
In PERT analysis, how many time estimates are typically used for each activity? —
Three (optimistic, most likely, and pessimistic time)
33.
What is the primary advantage of using PERT over CPM? —
PERT can handle uncertain activity durations, while CPM assumes fixed durations.
34.
An activity is on the critical path if its slack is: —
Zero
35.
What does PERT stand for in project management? —
Program Evaluation and Review Technique
36.
In PERT, the standard deviation of the project completion time is calculated by: —
Taking the square root of the sum of variances of activities on the critical path.
37.
In a directed network, an edge with capacity 5 means: —
A maximum of 5 units of flow can pass through this edge.
38.
What is the 'slack' or 'float' of an activity? —
The amount of time an activity can be delayed without delaying the project completion.
39.
The Latest Finish Time (LF) of an activity is determined by: —
The Latest Start Time of its succeeding activities.
40.
The Earliest Start Time (ES) of an activity is determined by: —
The Earliest Finish Time of its preceding activities.
41.
What is the 'optimistic time' (t_o) estimate in PERT? —
The shortest possible time to complete an activity, assuming ideal conditions.
42.
What is the fundamental principle of the Max-Flow Min-Cut Theorem? —
The maximum flow through a network is equal to the capacity of a minimum cut.
43.
In a CPM network, what is the 'critical path'? —
The sequence of activities that determines the minimum project completion time.
44.
The Ford-Fulkerson algorithm is used to find: —
The maximum flow in a network.
45.
What is the 'pessimistic time' (t_p) estimate in PERT? —
The longest possible time to complete an activity, assuming adverse conditions.
46.
What is the 'most likely time' (t_m) estimate in PERT? —
The time most likely to occur under normal conditions.
47.
What is the 'capacity' of a cut in a network? —
The sum of the capacities of the edges in the cut.
48.
What is the primary goal of network analysis techniques like CPM and PERT? —
To plan, schedule, and control projects to ensure timely completion.
49.
What is the purpose of 'dummy activities' in AOA network diagrams? —
To show dependencies correctly without consuming time or resources.
50.
What is a 'residual graph' used for in max-flow algorithms? —
To track the remaining capacity on edges after some flow has been sent.