Chapter 7: Ethical Decisions in software development

Question 1

acceptance

Answer 1

When an organization decides to accept a risk because the cost of avoiding the risk outweighs the potential loss of the risk. A decision to accept a risk can be extremely difficult and controversial when dealing with safety-critical systems because making that determination involves forming personal judgments about the value of human life, assessing potential liability in case of an accident, evaluating the potential impact on the surrounding natural environment, and estimating the system’s costs and benefits.

Question 2

agile development

Answer 2

A software development methodology in which a system is developed in iterations lasting from one to four weeks. Unlike the waterfall system development model, agile development accepts the fact that system requirements are evolving and cannot be fully understood or defined at the start of the project.

Question 3

annualized loss expectancy (ALE)

Answer 3

The estimated loss from a potential risk event over the course of a year. The following equation is used to calculate the annual loss expectancy: A× SLE = ALE. Where ARO is the annualized rate of occurrence, an estimate of the probability that this event will occur over the course of a year and SLE is the single loss expectancy, the estimated loss that would be incurred if the event happens.

Question 4

annualized rate of occurrence (ARO)

Answer 4

An estimate of the probability that a risk event will occur over the course of a year.

Question 5

avoidance

Answer 5

The elimination of a vulnerability that gives rise to a particular risk in order to avoid the risk altogether. This is the most effective solution but often not possible due to organizational requirements and factors beyond an organization’s control.

Question 6

best practice

Answer 6

A method or technique that has consistently shown results superior to those achieved with other means and that is used as a benchmark within a particular industry.

Question 7

black-box testing

Answer 7

A type of dynamic testing that involves viewing the software unit as a device that has expected input and output behaviors but whose internal workings are unknown (a black box).

Question 8

breach of warranty

Answer 8

When a product fails to meet the terms of its warranty.

Question 9

business information system

Answer 9

A set of interrelated components—including hardware, software, databases, networks, people, and procedures—that collects and processes data and disseminates the output.

Question 10

Capability Maturity Model Integration (CMMI) models

Answer 10

Collection of best practices that help organizations improve their processes.

Question 11

CMMI-Development (CMMI-DEV)

Answer 11

A specific application of CMMI frequently used to assess and improve software development practices.

Question 12

contributory negligence

Answer 12

When the plaintiffs’ own actions contributed to their injuries.

Question 13

decision support system (DSS)

Answer 13

A type of business information system used to improve decision making in a variety of industries.

Question 14

deliverable

Answer 14

Products created during various stages of the development process, including statements of requirements, flowcharts, and user documentation.

Question 15

dynamic testing

Answer 15

A QA process that tests the code for a completed unit of software by actually entering test data and comparing the results to the expected results.

Question 16

failure mode

Answer 16

A description of how a product or process could fail to perform the desired functions described by the customer.

Question 17

failure mode and effects analysis (FMEA)

Answer 17

An important technique used to develop ISO 9000-compliant quality systems by both evaluating reliability and determining the effects of system and equipment failures.

Question 18

hazard log

Answer 18

A logging and monitoring system used by safety engineers to track hazards from a project’s start to its finish.

Question 19

high-quality software system

Answer 19

Systems that are easy to learn and use because they perform quickly and efficiently; they meet their users’ needs; and they operate safely and reliably so that system downtime is kept to a minimum.

Question 20

integration testing

Answer 20

Software testing done after successful unit testing, where the software units are combined into an integrated subsystem that undergoes rigorous testing to ensure that the linkages among the various subsystems work successfully.

Question 21

ISO 9001 family of standards

Answer 21

A set of standards written to serve as a guide to quality products, services, and management. It provides a set of standardized requirements for a quality management system.

Question 22

mitigation

Answer 22

The reduction in either the likelihood or the impact of the occurrence of a risk.

Question 23

N-version programming

Answer 23

An approach to minimizing the impact of software errors by independently implementing the same set of user requirements N times (where N could be 2, 3, 4 or more); the N-versions of software are run in parallel; and, if a difference is found, a “voting algorithm” is executed to determine which result to use.

Question 24

product liability

Answer 24

The liability of manufacturers, sellers, lessors, and others for injuries caused by defective products.

Question 25

quality assurance (QA)

Answer 25

Methods within the development process that are designed to guarantee reliable operation of a product.

Question 26

quality management

Answer 26

The defining, measuring, and refining of the quality of the development process and the products developed during its various stages. The objective of quality management is to help developers deliver high-quality systems that meet the needs of their users.

Question 27

redundancy

Answer 27

The provision of multiple interchangeable components to perform a single function in order to cope with failures and errors.

Question 28

reliability

Answer 28

A measure of the rate of failure in a system that would render it unusable over its expected lifetime.

Question 29

risk

Answer 29

The potential of gaining or losing something of value. Risk can be quantified by three elements: a risk event, the probability of the event happening, and the impact (positive or negative) on the business outcome if the risk does actually occur.

Question 30

risk management

Answer 30

A logging and monitoring system used by safety engineers to track hazards from a project’s start to its finish.

Question 31

safety-critical system

Answer 31

A system whose failure may cause human injury or death.

Question 32

single loss expectancy (SLE)

Answer 32

The estimated loss that would be incurred if a risk event occurs.

Question 33

software defect

Answer 33

Any error that, if not removed, could cause a software system to fail to meet its users’ needs.

Question 34

software development methodology

Answer 34

A standard, proven work process that enables systems analysts, programmers, project managers, and others to make controlled and orderly progress in developing high-quality software.

Question 35

software quality

Answer 35

The degree to which a software product meets the needs of its users.

Question 36

static testing

Answer 36

A software-testing technique in which software is tested without actually executing the code. It consists of two steps—review and static analysis.

Question 37

strict liability

Answer 37

A situation in which the defendant is held responsible for injuring another person, regardless of negligence or intent.

Question 38

system safety engineer

Answer 38

Someone who has explicit responsibility for ensuring that a system will operate in a safe and reliable manner while meeting its users’ needs.

Question 39

system testing

Answer 39

Software testing done after successful integration testing, where the various subsystems are combined to test the entire system as a complete entity.

Question 40

transference

Answer 40

A risk management strategy in which the risk, should it happen, does not rest solely on one individual or organization. For example, a common way to accomplish risk transference is for an individual or an organization to purchase insurance, such as auto or business liability insurance. Another way to transfer risk is to outsource the risk by contracting with a third party to manage the risk.

Question 41

unit testing

Answer 41

A software-testing technique that involves testing individual components of code (subroutines, modules, and programs) to verify that each unit performs as intended.

Question 42

user acceptance testing

Answer 42

Software testing done independently by trained end users to ensure the system operates as expected.

Question 43

warranty

Answer 43

Assures buyers or lessees that a product meets certain standards of quality.

Question 44

waterfall system development model

Answer 44

A software development methodology that involves a sequential, multistage system development process in which development of the next stage of the system cannot begin until the results of the current stage are approved or modified as necessary.

Question 45

white-box testing

Answer 45

A type of dynamic testing that treats the software unit as a device that has expected input and output behaviors but whose internal workings, unlike the unit in black-box testing, are known.