Final Exam Review Geb Thomas

Information Systems Applications

Players in the Game System owners pay for the system to be built and maintained. System users use the system to perform or support the work to be completed. System designers design the system to meet the users’ requirements. System builders construct, test, and deliver the system into operation. Systems analysts facilitate the development of information systems and computer applications by bridging the communications gap that exists between nontechnical system owners and users and technical system designers and builders. IT vendors and consultants sell hardware, software, and services to businesses for incorporation into their information systems.

The Development Components

The FAST Development Process

Model-Driven Development

Rapid Application Development

Commercial Off-the-Shelf (COTS) Software Route

Requirements Analysis Phase in Which FoundCost Ratio Requirements1 Design3-6 Coding10 Development Testing15-40 Acceptance Testing30-70 Operation

The Ishikawa diagram is a graphical tool used to identify, explore, and depict problems and the causes and effects of those problems. It is often referred to as a cause-and-effect diagram or a fishbone diagram. Fishbone Diagram

Joint Requirements Planning (JRP) Joint requirements planning (JRP) is a process whereby highly structured group meetings are conducted for the purpose of analyzing problems and defining requirements. JRP is a subset of a more comprehensive joint application development or JAD technique that encompasses the entire systems development process. Participants Sponsor Facilitator Users and Managers Scribes I.T. Staff (These folks don’t contribute, unless spoken to)

Data Modeling

Entity Relationship Diagrams

Important Entity Concepts An entity is a class of persons, places, objects, events, or concepts about which we need to capture and store data. An attribute is a descriptive property or characteristic of an entity. Synonyms include element, property, and field. The data type for an attribute defines what type of data can be stored in that attribute. The domain of an attribute defines what values an attribute can legitimately take on. The default value for an attribute is the value that will be recorded if not specified by the user. Relationships Cardinality: minimum and maximum number of occurrences of one entity that may be related to a single occurrence of the other entity Degree: the number of entities that participate in the relationship.

Non-Specific Relationships

Another Non-Specific Relationship

Context Data Model MEMBER ORDER MEMBER TRANSACTION PRODUCT AGREEMENTPROMOTION responds to places binds is a has conducted generates features sells

Key-Based Data Model

Fully-Attributed Data Model

Data Normalization An entity is in first normal form (1NF) if there are no attributes that can have more than one value for a single instance of the entity. Any attributes that can have multiple values actually describe a separate entity, possibly an entity and relationship. An entity is in second normal form (2NF) if it is already in 1NF and if the values of all nonprimary key attributes are dependent on the full primary key—not just part of it. Any nonkey attributes that are dependent on only part of the primary key should be moved to any entity where that partial key is actually the full key. This may require creating a new entity and relationship on the model. An entity is in third normal form (3NF) if it is already in 2NF and if the values of its nonprimary key attributes are not dependent on any other non- primary key attributes. Any nonkey attributes that are dependent on other nonkey attributes must be moved or deleted. Again, new entities and relationships may have to be added to the data model.

Process Modeling

A Data Flow Diagram External Entity Data Store Data Flow Process

A Decomposition Diagram

Types of Events A function is set of related and ongoing activities of a business. An event (or transaction) is a logical unit of work that must be completed as a whole (as part of a function). An elementary process (or primitive process) is a discrete, detailed activity or task required to respond to an event. Usually, several such tasks must be completed to respond to an event.

Problems with DFDs

Illegal Data Flows

Database Design

Files Versus Databases File Information System Database (consolidated & integrated data from files) Information System Information System Information System Information System

Relational Databases

Structured Query Language (SQL) SELECT list_of_columns FROM tables[s] [WHERE search_conditions] SELECT * FROM products (* means all columns) SELECT ProductName, Unitprice * UnitsOnOrder as [Ordered Amount] FROM products WHERE UnitsOnOrder > 0 SELECT ‘The highest price is ’, max(unitprice) FROM Products

The Where Clause Comparison operators (=,,, and so on) Combinations or logical negations of conditions (AND, OR, NOT) –Where unitprice 2000 Ranges (Between, Not Between) –Where unitprice between 2000 and 5000 Lists (In, Not in) –Where state in (‘CA’, ‘IN’, ‘MD’)

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