System Synthesis + Design

Question 1

True or False: system synthesis is used to translate a functional architecture into and optimized physical software architecture.

Answer 1

True

Question 2

Modular designs have low ____, and high _____.

Answer 2

Coupling, Cohesion

Question 3

Modular designs have ____ coupling and ____ high cohesion. (High or Low)

Answer 3

Low, High

Question 4

True or False: Robust designs exclusively meet a highly specific set of requirements.

Answer 4

False:

Robust designs generally meet a wide range of requirements.

Question 5

What is the general systems engineering process?

Answer 5

1. Requirements analysis
2. Functional Allocation/Analysis
3. Synthesis/Design
4. Overall Analysis, Optimization, and Control.

Question 6

Systems synthesis creates a ___ for every WHAT and HOW WELL.

Answer 6

HOW

Question 7

True or False: Synthesis is generally NOT an iterative process.

Answer 7

False

Come on, everything in engineering centers around repetitiveness and iterativity.

Question 8

A ______ solution considers overall system risk, cost, technical maturity, and robustness for each possible subsystem combination.

Answer 8

Balanced

Question 9

List the Synthesis + Design Steps:

Answer 9

1. Functional Analysis
2. Allocated (derive) performance and resource reqs
3. Define Alternatives (physical and software)
4. Assess maturity levels of technology
5. Define interfaces
6. Estimate performance of combinations
7. Use performance-resource curves to identify break points
8. Determine driving reqs and reallocate if necessary
9. Select preferred design architecture, implementation plans, allocations, and expectations.

Question 10

Functional Analysis Steps:

Answer 10

1. Define system reqs
2. Functional Decomp
3. Create FFBD
4. Create TLA and assess functional durations

Question 11

True or False: Different subsystems designs don’t typically have different performance/resource allocations.

Answer 11

False, duh

Question 12

True or False: the first resource/performance allocations are usually optimal.

Answer 12

False, sub-optimal ITERATE

Question 13

When defining subsystem alternatives: you should start with a comparable subsystem for comparison

Answer 13

Yes

Question 14

What is TRL?

Answer 14

Technology Readiness Level:

a commonly used measure of technical maturity

Question 15

True or False: Schematic Block Diagrams are not primarily used to check for redundancy, and completeness.

Answer 15

False, they are.

Question 16

When defining interfaces, we should develop these two diagrams:
________
_________

Answer 16

1. N-Squared Diagram

2. Schematic Block Diagram

Question 17

True or False: cost utility curves have an asymptote

Answer 17

True

Question 18

True or False: increasing budget proportionally increases performance.

Answer 18

False, the curve has rate decay to zero

Question 19

The ____ _____ are those that are the most difficult to meet.

Answer 19

Driving Requirements

Question 20

Difference between mission requirements and allocated/derived requirements:

Answer 20

Mission Requirements (driving):
- cannot be varied
- cannot be optimized
- ex: the space flight system shall have a mass of no more the 5500 kg.
Derived Requirements:
- can be varied without necessarily changing the performance
- Can be reallocated for performance enhancement
- ex: The communications subsystem shall have a mass of no more than 90 kg. (fraction of system mass and may be changed, not total system mass - driving if a constraint)

Question 21

What is an MOE?

Answer 21

Measure of Effectiveness:

Metric used to assess risk, performance, lifecycle implications, and customer priorities to support decision making.

Question 22

True or False: better is not the enemy of good enough.

Answer 22

FALSE:

Better wants to kill good enough with an axe

Question 23

A good way to seek optimal system design is to ____ all subsystems _____.

Answer 23

Stress/test/push, equally

Question 24

True or False: it is inadvisable to try and share the developmental ‘pain’ between the subsystems during synthesis.

Answer 24

FALSE

We want to spread the pain like peanut butter over that shit.

Question 25

When seeking 'balanced' systems solutions: good _____ is required to acknowledge common goals of all team members.

Answer 25

Communication

Question 26

List 4 Good Synthesis Heuristics:

Answer 26

1. Low Coupling 2. High Cohesion 3. Low Connectivity 4. Magical 7

Question 27

Define: Low Coupling

Answer 27

Choosing subsystem boundaries so that each can be implemented independently.

Question 28

Define: High Cohesion

Answer 28

Grouping strongly related functions, segregate the unrelated ones.

Question 29

Define: Low Connectivity

Answer 29

Reducing the overall complexity and number of interfaces present.

Question 30

Define: Magical 7

Answer 30

Each level of a partitioned hierarchy should have 7 +/- 2 elements.

Question 31

True or False: it is generally easy to determine the boundary between hardware and software functions

Answer 31

False

Question 32

True or False: finding the boundary between data management with spacecraft and ground control is very difficult.

Answer 32

True

Question 33

A robust design reduces the effects of _____ and _______.

Answer 33

Uncertainty, variability

Question 34

A robust design ____ the effects of uncertainty or variability without ______ the uncertainty or variability itself. (same word)

Answer 34

Reduces

Question 35

What does sensitivity analysis do?

Answer 35

Assesses the performance of an element with variable input.

Question 36

The following is an example of a robust design: Input varies from 90 to 120V Output varies from 16 to 20V

Answer 36

Not Robust | Highly sensitive when looking at percentage fluctuations of the output.

Question 37

The following is an example of a robust design: Input varies from 90 to 120V Output varies from 17.9 to 18.05V

Answer 37

Not Robust | Percentage change of output very low.

Question 38

Robust designs ______ utility to gain performance over a wide range or resources & environments.

Answer 38

Sacrifice

Question 39

______ is a measure of the ability of a system to absorb changes in requirements, constraints or failures while reducing the impacts on the performance, functionality or composition of the mission or system.

Answer 39

Robustness

Question 40

System synthesis produces a _____ architecture from the _______ architecture.

Answer 40

Physical, Functional

Question 41

Name a good way to seek optimal design:

Answer 41

Stressing all subsystems equally.

Question 42

True or False: Maintaining a decision database and formally reviewing it at milestones is a part of functional analysis.

Answer 42

False: | This is a part of system synthesis and design

Question 43

We can ______ resources/performance to manage and meet the driving requirements.

Answer 43

Reallocate

Question 44

True or False: subsystems should have high complexity, low cohesion, and low connectivity.

Answer 44

False | low comp, high cohesion