Final Exam CEN 3820

What is the goal of data and process modeling?

To show what the system must do to transform data into useful info and create a logical model that meets user needs.

What are the four main tools used in data and process modeling?

Functional Decomposition Diagram (FDD), Data Flow Diagram (DFD), Data Dictionary, and Process Descriptions.

What is a Functional Decomposition Diagram (FDD)?

A visual tool that breaks down a system into smaller, manageable parts until reaching a functional primitive.

What does a Data Flow Diagram (DFD) show?

How data moves through an information system, what happens, not how it happens.

What are four DFD symbols?

Process (circle), data flow (arrow), data store (open rectangle), entity (square/rectangle)

What is a black hole error in a DFD?

A process with input but no output

What is a spontaneous generation in a DFD?

A process that produces output without any input

What is a gray hole in a DFD?

A process whose input is insufficient to product its output

What are the three steps to create DFDs?

1- Draw context diagram, 2- Draw Diagram 0 DFD, 3- Draw lower-level DFDs

What is leveling in DFDs?

Breaking processes into more detail levels until functional primitives are reached.

What is balancing in DFDs?

Ensuring parent and child diagrams have matching inputs and outputs

What is a data dictionary?

Repository that defines and describes all data elements, flows, stores, and processes in the system

What is a data element?

The smallest unit of data that has meaning (like a field)

What is a record (data structure)?

Collection of related data elements

What is structured English?

Pseudocode-like language used to describe business logic in clear steps.

What is a decision table used for?

To show all combinations of conditions and their resulting actions.

What is a decision tree?

Graphical representation of conditions and actions, branching out like a tree.

What is the difference between logic and physical models?

Logical shows what system does, physical shows how it’s implemented.

What are four models in the Four-Model Approach?

Physical current, logical current, logical new, and physical new system models

What is object-oriented analysis (OOA)?

Method to describe systems by identifying objects and their interactions

What is the end product of OOA?

An object model

What is UML?

Unified Modeling Language, used to visualize and document object oriented systems.

What is an object?

Person, place, thing, or event that include both data and behavior.

What are attributes?

Characteristics or properties of an object

What are methods?

Tasks or functions that an object performs

What is a message in OOP?

Command telling an object to perform a method

What is encapsulation?

Keeping all data and methods of an object self-contained

What is polymorphism?

The same message produces different results depending on the object

What is inheritance?

A child object derives attributes or methods from a parent object

What is a class?

A category of objects that share common attributes and methods

What is an instance?

Specific object within a class

What is the relationship between superclass and subclass?

Subclass = more specific category within a superclass

What is an object relationship diagram (ORD)?

A diagram showing how objects interact to perform system functions

What is a use case?

Describes a specific business function or process and its steps

What is an actor in a use case?

External entity that interacts with the system

What is a use case diagram?

Visual summary showing relationships between use cases and actors.

What is a class diagram?

Detailed view showing classes their attributes, methods, and relationships

What is cardinality in a class diagram?

It shows how many instances of a class relate to another

What is a sequence diagram?

A dynamic model showing interactions between objects over time

What are the parts of a sequence diagram?

Class (rectangle), lifeline (dashed line), message (arrow), focus (narrow rectangle)

What is a state transition diagram?

Shows how an object moves between states in response to events

What is an activity diagram?

Flowchart showing the sequence of actions or activities

What are dynamic modeling tools?

Sequence, state transition, and activity diagrams, used to show system behavior over time

What is the role of CASE tools?

To automate and manage the creation of object models and diagrams efficiently

What is Software as a Service (SaaS)?

A software deployment model where the application is hosted online and provided to customers over the internet

Key characteristics of traditional system development?

Designed for local/WAN networks, compatibility-focused, uses internet features as add-ons rather than core

Key characteristics of web-based development?

Designed in an internet framework treats Web as platform, requires middleware to connect with legacy systems

What is Web 2.0?

The second generation of the web enabling dynamic collaboration and information sharing

Examples of Web 2.0 tools?

Wikis, blogs, social networking sites

What is cloud computing?

Online software and data environment supported by large-scale computing; considered the ultimate form of SaaS

What is the “Make or Buy” decision?

Choosing between in-house software development and outsourcing/purchasing software

Why do companies outsource (including offshore)?

Lower costs; however, offshore outsourcing includes additional risks

Why develop software in-house?

Meets unique business needs, minimizes policy changes, fits existing constraints, builds internal expertise

Benefits of purchasing a software package?

Lower cost, faster implementation, proven reliability, vendor upgrades, less technical staff required

What is software customization?

Modifying a purchased package to meet business needs, via vendor or in-house modifications

What are user applications?

Custom productivity tools created by users or IT using software like Excel/Access for specific tasks

What is the system analyst’s role in selecting hardware/software?

Evaluate alternatives, eliminate poor options, rank feasible ones, present best choices to management

What is payback analysis?

Measures how long until system benefits repay development costs

What is ROI?

Rate comparing net benefits to the total cost of the project

What is NPV?

Net present value, benefits minus costs, after adjusting for time value using discounting

What is an RFP?

Request for proposal, describes company needs and required system features.

What is an RFQ?

Request for quotation, used when the product is already chosen and pricing/bids are needed

What is benchmarking in software selection?

Testing a package to determine if it can handle required transaction volumes efficiently

What is TCO?

Total Cost of Ownership, includes purchase, support, maintenance, and operational costs

What is a system requirements document?

A formal specification including requirements, logic model, considered alternatives, and recommendations

What occurs during the presentation to management?

Alternatives are summarized, recommended solution is explained, questions addressed, and final decisions made

What is logical vs. physical design?

Logical = what system must do, physical = how system will be implemented

What is the best practice order for system design tasks?

Data design —> user interface —> input/output —> architecture/code modules

Three goals of system design?

Effective (meets requirements), reliable (handles errors), maintainable (easy to modify)

What is an audit trail?

A report tracking changes to critical data values

Why avoid hard-coded values?

To improve flexibility and reduce the need for re-testing after changes

What is modular design?

Designing components that perform a single function, improves clarity and maintainability

What is the main trade-off in design decisions?

Quality vs. cost-avoiding short-term savings that cause long-term expenses

What is a prototype?

Early, working version of a system used to refine requirements through repeated cycles

System prototyping vs design prototyping?

System: evolves into final system

Design/throwaway: used for requirements, then discarded

Examples of prototyping tools?

CASE tools, application/report/screen generators, 4GLs (like SQL), and 4G development environments

Current major trends in IT software development?

Increase focus on software quality, increase emphasis on project management, rise of SOA, increase in open-source tools, more use of web services, continued use/evolution of dynamic languages

Difference between file processing systems and database systems?

File systems store data in separate files, database systems use linked tables that provide flexibility and efficiency

What are the major problems with file processing?

-Data redundancy

-Data integrity issues

-Rigid data structure

List types of files in file processing

-Master file: permanent data

-Table file: state reference data

-Transaction file: daily operations

-Work file: temporary

-Report file: holds reports

-Security file: backup

-History file: archives

Advantages of database systems?

-Flexible data sharing

-Enterprise-wide support

-Controlled redundancy

-Scalability

-Better client/server support

-Security

-Programmer productivity

-Data independence

What are open database connectivity and java database connectivity used for?

-ODBC: vendor-neutral data exchange

-JDBC: java-based data exchange with SQL databases

What is a primary key?

Unique identifier for record

What is a candidate key?

A field that could serve as the primary key

What is a foreign key?

Field that links tables by matching a primary key in another table

What is a secondary key?

Non-unique field used for retrieving multiple records

What is referential integrity?

Prevents entering a foreign key unless it matches an existing primary key to avoid orphan records

What is normalization?

Organizing tables to reduce redundancy and improve integrity

What is 1NF?

Table w/no repeating groups

What is 2NF?

Table is in 1NF and non-key fields fully depend on the entire primary key

What is 3NF?

Table is in 2NF and no non-key field depends on another non-key field

Types of codes?

-Sequence

-Block sequence

-Alphabetic/mnemonic

-Significant digit

-Derivation

-Cipher

-Action

Guidelines for developing good codes?

-Keep concise

-Allow expansion

-Keep stable

-Unique

-Sortable

-Avoid confusing characters

-Meaningful

-Single-purpose

-Consistent across systems

What is an object oriented database (OODB)?

Stores objects with unique object identifiers; supports OO analysis; maintained by Object Management Group.

What is a data warehouse?

Integrated storage of data from multiple systems for analysis and decision making

What is data mining?

Software analyzing large data sets to find patterns and relationships

Difference between logical and physical storage

Logical- what users see

Physical- actual hardware-level binary storage

ASCII/EBCDIC vs Unicode?

ASCII/EBCDIC = 1 byte/character; unicode = 2 bytes and supports 65k+ multilingual characters

Recommended date storage format?

ISO format: YYYYMMDD

What DBMS controls protect data?

Subschemas, passwords, encryption, audit trials, backup and recovery.