Systems Analysis Final

CEN 3820 - System Analysis & Design

When drawing a context diagram, standardized names should be used within each set of symbols.

False

In a data flow diagram (DFD), a process symbol can have only one outgoing data flow.

False

In a data flow diagram (DFD), a data flow must have a process symbol on at least one end.

True

Spontaneous generation, black holes, and gray holes are impossible logically in a data flow diagram.

True

Attributes are similar to adjectives that describe the characteristics of an object.

True

Data flow diagram entities also are called terminators because they are data origins or final destinations.

True

Diagram 0 (the numeral zero, and not the letter O) provides an overview of all the components that interact to form the overall system.

True

_____ is the process of drawing a series of increasingly detailed data flow diagrams (DFDs), until all functional primitives are identified.

Leveling

A use case represents the steps in a specific business function or process.

True

Processes contain the business logic, also called business rules, which transforms the data and produces the required results.

True

Class diagrams evolve into code modules, data objects, and other system components.

True

A class diagram resembles a horizontal flowchart that shows the actions and events as they occur.

False

Just as objects are similar to adjectives, attributes resemble verbs that describe what and how an object does something.

False

To draw a context diagram, you start by placing a single process symbol on the top right corner of the page.

False

Among the symbols in the accompanying figure, a _____ receives input data and produces output that has a different content, form, or both.

process

In a state transition diagram, the circle at the right with a hollow border is the initial state.

False

To reach prospective customers and investors, companies use a live or prerecorded webcast, which is an audio or video media file distributed over the Internet.

True

In very complex systems, the prototype can become unwieldy and difficult to manage.

True

When determining outsourcing fees, a _____ uses a set fee based on a specified level of service and user support.

fixed fee model

A _____ language feature allows users to type commands or requests in normal text phrases.

natural

Typically, customers purchase licenses that give them the right to use software under the terms of the license agreement.

True

A subscription model charges a variable fee based on the volume of transactions or operations performed by the application.

False

Some forms use a _____ that contains icons or buttons that represent shortcuts for executing common commands.

toolbar

Which is true of a traditional systems development environment?

Many applications require substantial desktop computing power and resources.

The _____ environment enhances interactive experiences, including wikis and blogs, and social networking applications.

Web 2.0

Mergers and acquisitions typically have no impact on clients and customers of large, financially healthy firms.

False

An interface designer does not need to understand the underlying business functions or how the system supports individual, departmental, or enterprise goals.

False

To develop a user-centered interface, a designer must learn to think like a user and see the system through a user's eyes.

True

In a traditional systems development environment, security issues usually are less complex than with web-based systems, because the system operates on a private company network, rather than the Internet.

True

A firm that offers outsourcing solutions is called a _____.

service provider

Sensitive data can be encrypted, or coded, so only users with decoding software can read it.

True

Human-computer interaction (HCI) describes the relationship between computers and the people who use them to perform their jobs.

True

Web-based systems are popular because they offer ease of access, cost-effectiveness, and worldwide connectivity.

True

Like a primary key, a foreign key must be unique.

False

Audit log files, which record details of all accesses and changes to a file or database, can be used to recover changes made since the last backup.

True

A repeating group is a set of one or more fields that can occur only once in a single record, with each occurrence having the same value.

False

The three normal forms constitute a progression in which second normal form represents the best design.

False

Most magazine subscription codes are action codes.

False

Migrating a traditional database design to the web can require design modification, additional software, and some added expense.

True

filed-oriented system // file processing system

stores and manages data in one or more separate files

relational database

a database in which tables are related by common fields, creating a unified data structure that provides improved data quality and access

relational model

a model used in relational databases. Was introduced in the 1970s and became popular because it was flexible and powerful.

economy of scale

the inherent efficiency of high-volume processing on larger computers. Database design allows better utilization of hardware. If a company maintains a enterprise-wide database, process is less expensive using a powerful mainframe server instead of using several smaller computers.

Database Administrator (DBA)

Someone who manages a database management system (DBMS).
The DBA assesses overall requirements and maintains the database for the benefit of the entire organization rather than a single department or user.

Data Manipulation Language (DML)

a DML controls database operations, including storing, updating, receiving, and deleting data. Most commercial DBMS uses a DML. (Oracle, IBM's DB2)

query language

Allows a user to specify a task without specifying how the task will be accomplished. Some query languages use natural language commands that resemble ordinary english sentences.

query by example (QBE)

a language allows the user to provide an example of the data requested.

Structured Query Language (SQL)

a query language that allows PC users to communicate with servers and mainframe computers.

Database Management System (DBMS)

a collection of tools, features and interfaces that enables users to add, update, manage, access, and analyze data in a database

schema

the complete definition of a database, including descriptions of all fields, records, and relationships.

subschema

a view of the database used by one or more systems of users. A subschema defines only those portions of the database that a particular system or user needs or is allowed to access.

Open Database Connectivity (ODBC)

An industry-standard protocol that makes it possible for software from different vendors to interact and exchange data.

Java Database Connectivity (JDBC)

a standard that enables Java applications to exchange data with any database that uses SQL statements and is OCDB compliant.

table // file

Each file or table contains data about people, places, things, or events that interact with the information system

common field

An attribute that appears in more than one entity. Common fields can be used to link entities in various types of relationships.

record // tuple

a set of related fields that describes one instance or member of an entity, such as one customer, one order, one product. A record might have one or dozens of fields. depending on what information is needed.

key fields

Used during system design to organize, access, and maintain data structures. The four types of key fields are: primary keys, candidate keys, foreign keys, secondary keys.

primary key

A field or combination of fields that uniquely and minimally identifies a particular member of an entity.

EG: in a customer table the customer number is a unique primary key because no two customers can have the same customer number. The key is also minimal because it contains no information beyond what is needed to identify the customer.

combination key

A type of data validation check that is performed on two or more fields to ensure that they are consistent or reasonable when considered together. Even though all the fields involved in a combination check might pass their individual validation checks, the combination of the field values might be inconsistent or unreasonable.

composite key // concatenated key // multivalued key.

Sometimes it is necessary for a primary key to consist of a combination of fields. In that case, the primary key is called a combination key, composite key, concatenated key, multivalued key.

candidate key

Sometimes it is possible to have a choice of fields or field combinations to use as the primary key. Any field that could serve as a primary key is called a candidate key.

nonkey field

Any field that is not a primary key or a candidate key

foreign key

A field in one table that must match a primary key value in another table in order to establish the relationship between the two tables.

secondary key

Field or combination of fields that can be used to access or retrieve records. Secondary keys are not unique. EG: to access records for only those customers in a specific postal code, the postal code field could be used as a secondary key.

Referential Integrity

a type of validity check. IT is a set of rules that avoids data inconsistency and quality problems.

Orphan

An unassociated or unrelated record or field. An orphan could be created if a customer order was entered in an order table in where that customer did not already exist in the customer table. Referential integrity would prevent the creation of this orphan.

Entity Relationship Diagram (ERD)

a graphical model of the information system that depicts the relationships among system entities.

1:1 relationship

a type of entity relationship. Exists when exactly one of the second entity occurs for each instance of the first entity.

1:M

A type of entity relationship. Exists when one occurrence of the first entity can be related to to many occurrences of the second entity, but each occurrence of the second entity can be associated with only one occurrence of the first entity.

M:N

A type of entity relationship. A many-to-many relationship, abbreviated M:N, exists when one instance of the first entity can be related to many instances of the second entity, and one instance of the second entity can be related to many instances of the first entity.

Associative Entity

An entity type that has its own set of attributes and characteristics. Associative entities are used to link between many-to-many (M:N) relationships.

cardinality notation

Code that shows relationships between entities

Crow's Foot notation

A type of cardinality notation. It is called crow's foot notation because of the shapes, which include circles, bars, and symbols, that indicate various possibilities.

A single bar indicates one, a double bar indicates one and only one, a circle indicates zero, and a crow's foot indicates many.

Normalization

A process by which analysts identify and correct inherent problems and complexities in their record designs.

table design

Specifies fields and identifies the primary key in a particular table or file

standard notation format

A representation that makes designing tables easier as it clearly shows a table's structure, fields, and primary key.

repeating group

A set of one or more fields that can occur any number of times in a single record, with each occurrence having different values.

unnormalized

A record that contains a repeating group, which means that a single record has multiple occurrences of a particular field, with each occurrence having different values.

First Normal Form (1NF)

A record is said to be in first normal form (1NF) if it does not contain a repeating group (a set of data items that can occur any number of times in a single record).

functionally dependent

Functional dependence is an important concept for understanding the second normal form (2NF). The field X is said to be functionally dependent on the field Y if the value of X depends on the value of Y. For example, an order date is dependent on an order number; for a particular order number, there is only one value for the order date. In contrast, the product description is not dependent on the order number. For a particular order number, there might be several product descriptions, one for each item ordered.

Second Normal Form (2NF)

A record design is in second normal form (2NF) if it is in 1NF and if all fields that are not part of the primary key are dependent on the entire primary key. If any field in a 1NF record depends on only one of the fields in a combination primary key, then the record is not in 2NF. A 1NF record with a primary key that is a single field is automatically in 2NF.

Third Normal Form (3NF)

A record design is in 3NF if it is in 2NF and if no nonkey field is dependent on another nonkey field. A nonkey field is a field that is not a candidate key for a primary key.

code

a set of letters or numbers that represents a data item. Codes can be used to simplify output, input, and data formats.

sequence code

Numbers or letters assigned in a specific order. Sequence codes contain no additional information other than an indication of order of entry into a system

block sequence codes

cipher that uses blocks or numbers for different classifications.

Alphabetic codes

Uses alphabet letters to distinguish one item from another based on a category, an abbreviation, or an easy-to-remember value, called a mnemonic code

category codes

identify a group of related items. For example, a local department store uses a two-character category code to identify the department in which a product is sold: GN for gardening supplies, HW for hardware, and EL for electronics.

abbreviation codes

alphabetic abbreviations. For example, standard state codes include NY for New York, ME for Maine, and MN for Minnesota.

Significant digit codes

Distinguish items by using a series of subgroups of digits. Postal codes, for example, are significant digit codes

derivation code

combining data from different item attributes, or characteristics, to build the code. Most magazine subscription codes are derivation codes.

Cipher codes

Uses a keyword to encode a number. A retail store, for example, might use a 10-letter word, such as CAMPGROUND, to code wholesale prices, where the letter C represents 1, A represents 2, and so on. Thus, the code, GRAND, indicates that the store paid $562.90 for the item.

Action code

Indicates what action is to be taken with an associated item. For example, a student records program might prompt a user to enter or click an action code such as D (to display a record), A (to add a record), and X (to exit the program).

Data warehouse

An integrated collection of data that can support management analysis and decision making.

Data mart

A specialized database designed to serve the needs of a specific department, such as sales, marketing, or finance. Each data mart includes only the data that users in that department require to perform their jobs.

Data mining

looking for meaningful patters and relationships among data. For example, data mining software could help a consumer products firm identify potential customers based on their prior purchases.

clicks to close

The average number of page views to accomplish a purchase or obtain desired information.

clickstream storage

Recording web visitor behavior and traffic trends for later data mining use.

market base analysis

a type of analysis that can detect patters and trends in large amounts of data.

logical storage

Refers to information as seen through a user's eyes, regardless of how or where that information is organized or stored.

physical storage

Information storage mechanism that is strictly hardware-related, because it involves the process of reading and writing binary data to physical media, such as a hard drive, flash drive, or DVD.