Systems Analysis & Design Exam 2

Agile Modeling

a collection of innovative, user-centered approaches to system development

Prototyping

an information-gathering technique useful in seeking user reactions, suggestions, innovations, and revision plans

Throwaway Prototypes

patched-up prototypes
nonoperational prototypes

Evolutionary Prototypes

first-of-a-series prototypes
selected features prototypes

honest involvement
communicate the purpose of the prototype clearly
get suggestions and feedback for changing, expanding the prototype and innovation

users' role in prototyping

communication
simplicity
courage
feedback

agile values

satisfy the customer
embrace change
deliver functioning software incrementally and frequently
work together daily
trust motivated individuals
face-to-face conversation
getting software to work
continuous, regular, & sustainable development
agility and mindful design
self-organizing teams
rapid feedback
quality
adjust behavior
simple

basic principles of agile modeling

short release
40-hour workweek
pair programming
on-site customer

agile core practices

time
cost
scope
quality

agile resources

coding
testing
designing
listening

agile activities

listen for user stories
draw a logical workflow model
create new user stories based on the logical model
develop some display prototypes
create a physical data model using feedback from the prototypes and logical workflow diagrams

agile development process

spoken interaction between developers and users
seeking first and foremost to identify valuable business user requirements
the goal is prevention of misunderstandings or misinterpretations of user requirements

writing user stories

pigs

highly committed members of the sprint cycle
scrum master, development team, product owner, other team members

chickens

contributing members of the sprint cycle
customer, vendor, executives

Product Owner

owns the product backlog

Scrum Master

owns the scrum process

rugby

sport scrum comes from

Burndown Chart

shows the amount of work that has been completed in an epic or sprint, and the total work remaining

1. customer reads story and development team asks questions
2. team estimates and tests
3. team discusses
4. team estimates and repeats steps until a consensus is reached

Agile steps

short releases allow evolution
pair programming enhances quality
onsite customers are mutually beneficial
40-hour work week improves effectiveness
balanced resources and activities support goals
agile values are crucial to success

lessons learned from Agile

Kanban

displays and visualizes task workflows with cards used to control the flow of production through a factory

card, visual board, or sign

meaning of Kanban

Kaizen

continuous improvement that involves all participants.

good change or improvement

meaning of Kaizen

quick development
user-oriented
teamwork
less confusing
flexible
satisfying
rewards small accomplishments
provides feedback
adaptable

Scrum advantages

documenting features improperly
releasing products with errors
releasing products too soon
completing the spring backlog under pressure
geographically dispersed team
special skills may be required
hard to replace team members

Scrum disadvantages

DevOps (Development Operations)

the practice of blending the tasks performed by the development and IT operations groups to enable faster and more reliable software releases.

decrease the deployment time for newly developed applications
maximize profit by rapidly addressing market opportunities and getting customer feedback in a timely manner
minimize maintenance costs

DevOps (Development Operations) advantages

5 to 10 times more productive than the worst ones

based on their study of a group of programmers, Davis and Naumann claim that the best programmers are...

fit of dev team culture
best timing
training costs
client's reaction
impact of agile methods
individual rights of programmers/analysts

risks of adopting new IS

entity
process
data flow
data store

4 data flow diagram symbols

5 +- 2 (3 to 7)

number of processes per level

freedom from committing to technical implementations too early
understanding of interrelatedness of systems and subsystems
communicating current system knowledge to users
analysis of the proposed system

advantages of the data flow approach

External Entities

represent another department, a business, a person, or a machine
a source or destination of data, outside the boundaries of the system
should be named with a noun

Data Flow

shows movement of data from one point to another
described with a noun
arrowhead indicates the flow direction
represents data about a person, place, or thing

Process

denotes a change in or transformation of data
represents work being performed in the system
verb-adjective-noun

Data Store

symbol not included on context level
a depository for data that allows examination, addition, and retrieval of data
named with a noun
represents a database, computerized file, filing cabinet

1. make a list of business activities and determine various flows, entities, processes, and data stores
2. create a context diagram
3. draw Diagram 0
4. create a child diagram
5. check for errors
6. develop a physical data flow diagram
7. partition the physical data flow diagram

steps in developing data flow diagrams

data flow touches a process

requirement of data flow

logical focuses on the business and business activities
physical focuses on how a system is implemented

difference between logical and physical data flow diagrams

create
read
update
delete

C.R.U.D.

CRUD Matrix

the activities that must be present in a system for each master file
represents where each of the processes occurs in a system

Data Dictionary

a reference work of data about data
collects and coordinates data terms, and confirms what each term means to different people in the organization

"is composed of"

equal sign

"and"

plus sign

repetitive elements

braces {}

either/or situation

brackets []

optional element

parentheses ()

Base Element

one that has been initially keyed into the system

Derived Element

one that is created by a process, usually as the result of a calculation or a series of decision-making statements

Data Truncation

if the element is too small it will be shortened and could affect the system outputs

Structured Decision Analysis Methods

promote completeness, accuracy, and communication

reduce process ambiguity
obtain a precise description of what is accomplished
validate the system design

goals of producing process specification

Sequential Structure

a block of instructions in which no branching occurs

Decision Structure

only IF a condition is true, complete the following statements; otherwise, jump to the ELSE

Case Structure

a special type of decision structure in which the cases are mutually exclusive (if one occurs, the others cannot)

Iteration {}

blocks of statements that are repeated until done
entries become DO WHILE, DO UNTIL, or PERFORM UNTIL

Sequence

a simple sequence of statements MOVE, ADD, and SUBTRACT

Selection []

entries become IF...THEN...ELSE statements

Decision Trees

used when complex branching occurs in a structured decision process
useful when it is essential to keep a string of decisions in a particular sequence

the order of checking conditions and executing actions is immediately noticeable
conditions and actions of decision trees are found on some branches but not on others
compared to decision tables, decision trees are more readily understood by others in the organization

decision tree advantages

Structured English (Pseudocode)

use when there are many repetitious actions or when communication to end users is important

Decision Tables

use when a complex combination of conditions, actions, and rules are found or you require a method that effectively avoids impossible situations, redundancies, and contradictions

Object-Oriented Analysis and Design

works well in situations where complicated systems are undergoing continuous maintenance, adaptation, and design
objects, classes are reusable

Unified Modeling Language

U.M.L.

Unified Modeling Language (UML)

an industry standard for modeling object-oriented systems

Object Oriented Analysis

O.O.A.
uses use cases

Object Oriented Design

O.O.D.

Object Oriented Programming

O.O.P.

Reusability

recycling of program parts should reduce the costs of development in computer-based systems

Maintaining Systems

making a change in one object has a minimal impact on other objects

Objects

persons, places, or things that are relevant to the system being analyzed
may be customers, items, orders, and so on
may be GUI displays or text areas on a display

Classes

defines the set of shared attributes and behaviors found in each object in the class
should have a name that differentiates it from all other classes

Instantiate

when an object is created from a class

Attribute

describes some property that is possessed by all objects of the class

Method

an action that can be requested from any object of the class

class
responsibilities
collaborators

C.R.C.

CRC Cards

used to represent the responsibilities of classes and the interaction between the classes

things
relationships
diagrams

UML concepts and diagrams

Structural Things

classes, interfaces, use cases, and other elements that provide a way to create models
they allow the user to describe relationships

Behavioral Things

describe how things work
interactions and state machines

Group Things

used to define boundaries

Annotational Things

can add notes to the diagrams

Structural Relationships

tie things together in structural diagrams
dependencies, aggregations, associations, generalizations

Behavioral Relationships

used in behavioral diagrams
communicates, includes, extends, generalizes

Structural Diagrams

used to describe the relation between classes
class diagrams, object diagrams, component diagrams, deployment diagrams

Behavioral Diagrams

used to describe the interaction between people
(actors) and a use case (how the actors use the
system)
use case diagrams, sequence diagrams, collaboration diagrams, statechart diagrams, activity diagrams

Communication Diagrams

show the same information that is depicted in a sequence diagram but emphasize the organization of objects rather than the time ordering

Generalization

describes a relationship between a general kind of thing and a more specific kind of thing
described as an "is a" relationship
used for modeling class inheritance and
specialization

General Class

a parent, base, or superclass

Specialized Class

a child, derived, or subclass

Inheritance

helps to foster reuse
helps to maintain existing program code

Polymorphism

the capability of an object-oriented program to
have several versions of the same method with
the same name within a superclass/subclass
relationship

overrides the superclass method

the subclass method...

the most specific one is used

when attributes or methods are defined more
than once...

reusability
maintenance

pros of UML

high cost
steep learning curve
complicated

cons of UML

Associative Class

an association that has attributes or operations of its own or that participates in relationships with other classes

Extreme Programming (XP)

a form of agile software development that promotes incremental development of a system using short development cycles to improve productivity and to accommodate new customer requirements

HTML

hypertext markup language
a language used to create web pages