Systems design chapter 6

Question 1

Data flow diagram

Answer 1

Represents sys requirements as processes, external agents, data flows, and data stores

Question 2

External agent

Answer 2

Person or org outside the sys boundary that supplies data inputs or accepts data outputs

Question 3

Process

Answer 3

Symbol on a dfd that represents an algorithm or procedure by whih data inputs are transformed into data outputs

Question 4

Data flow

Answer 4

An arrow on a dfd that represents data movement among processes, data stores, and external agents

Question 5

Data store

Answer 5

A place where data is held pending future access by one or more processes

Question 6

Traditional approach

Answer 6

System of processes, processes interact with data entities, processes accept inputs and produce outputs.

Question 7

OO approach

Answer 7

System is collection of interacting object, objects interact with people and each other, objects send and respond to messages.

Question 8

Level of abstraction

Answer 8

Any modeling technique that breaks the system down into a hierarchical set of increasingly more detailed models.

Question 9

Context diagram

Answer 9

A dfd that summarizes all processing activity within the system in a single process symbol

Question 10

Data flow diagram DFD

Answer 10

Represents sys requirements as processes, external agents, data flows, and data stores

Question 11

Data flow diagram DFD

Answer 11

Represents sys requirements as processes, external agents, data flows, and data stores

Question 12

DFD fragment

Answer 12

A DFD that represents the system response to one event withina single process symbol

Question 13

Event-partitioned system model or diagram 0

Answer 13

A DFD that models system requirements using a single process for each event in a system or subsystem.

Question 14

Physical and logical DFDs

Answer 14

DFDs can be either physical system model, a logical system model or a combination of both.

Question 15

Information overload

Answer 15

Too much information at one time

Question 16

Rule 7+-2

Answer 16

Modeling rule that limits the number of components or connections to no more than nine

Question 17

Minimization of interfaces

Answer 17

Simplicity by limiting the number of of connections between model components.

Question 18

Balancing

Answer 18

Equivalence of FAA content between data flows entering and leaving a process and data flows entering and leaving a process decomposition DFD

Question 19

Black hole

Answer 19

Process or data store with a data input that is never used to produce a data output.

Question 20

Miracle

Answer 20

Process or data store with a data element that is created out of nothing.

Question 21

Structured English

Answer 21

Writing process specifications that combines structured programming techniques with narrative English.

Question 22

Decision table

Answer 22

A table representation of processing logic containing decision variables, decision variable values and actions or formulas

Question 23

Decision tree

Answer 23

A graphical description of process logic that uses lines organized like branches of a tree.

Question 24

Data flow definition

Answer 24

Text description of a data flows content and internal structure.

Question 25

Data store definitions

Answer 25

Data store on the DFD represents a data entity on the ERD no separate definition iOS usually needed. If no ERD link analyst defines data store as a collection of elements.

Question 26

Data element definitions

Answer 26

Describes a data type such as string, integer, floating point, or Boolean.

Question 27

Data dictionary

Answer 27

A repository for definitions of data flows, data elements, and data stores.

Question 28

DFD summary

Answer 28

4 block puzzle with DFD, ERD, process definitions, data definitions.

Question 29

Location diagram

Answer 29

A diagram or map that identifies all of the processing locations off a system

Question 30

Activity-location matrix

Answer 30

A table that describes the relationship between processes and the locations in which they are performed.

Question 31

Activity data matrix

Answer 31

A table that describes stored data entities the locations of which they are accessed, and the nature of the accesses.

Question 32

CRUD

Answer 32

Create read update delete