Systems Design Chapter 02 Flashcards
Project
A planned undertaking that has a beginning and an end that produces a desired result or product
SDLC - Systems Development Life Cycle
A process of building, deploying, using, and updating an information system
Predictive Approach
an SDLC approach that assumes project can be planned & organized in advance and it is developed according to plan
Adaptive Approach
flexible approach, assuming project cannot be planned in advance, must be modified as it progresses.
Project Planning Phase
Identify scope of new system, ensure project is feasible, develop a schedule, resource plan, and budget for the remainder project
- Define Problem
- Produce Schedule
- Confirm Feasibility
- Staff Project
- Launch Project
Analysis Phase
Understand and document the business needs and the processing requirements of the new system. (discovery & understanding)
- Gather information
- Define Sys Requirements
- Build Prototypes for discovery of requirements
- Prioritize requirements
- Generate and evaluate alternatives
- Review recommendations with management
Design Phase
To design the solution system based on the reqirements defined and decisions made during analysis.
- Design & integrate network
- Design the application architecture
- Design the user interface
- Design the system interface
- Design & integrate the database
- Prototype for design details
- Design and integrate the system controls
Implementation Phase
activities include programming, testing, and installing the system
- Construct software components
- Verify and test
- Convert data
- Train users and document the system
- Install the system
Support Phase
Keep the system running. Not part of initial development but is considered part of the SDLC.
- Maintain the system
- Enhance the system
- Support the users
Traditional SDLC Project Phases
Project planning, Analysis, Design, Implementation, and Support
Waterfall Model
Most predictive of SDLC approaches. Each phase is completed before starting next (still predictive)
Modified Waterfall Model
Sill predictive but phases overlap (still predictive)
Sprial Model
Adaptive SDLC approach that cycles over and over thru development activities till project is complete
Prototype
premlimary working model showing some aspect of a larger system
Iteration
Development process in which work activities-analysis, design, implementation are done again and again on different system components. They are repeated til the system is closer to what is ultimately needed.
Sprial Model
Adaptive SDLC approach that cycles over and over thru development activities till project is complete
Prototype
premlimary working model showing some aspect of a larger system
Iteration
Development process in which work activities-analysis, design, implementation are done again and again on different system components. They are repeated til the system is closer to what is ultimately needed.
Project
A project with beginning and end that produces a result or product
Incremental Development
an approach that completes parts of a system in several iterations and then puts them into operation.
Problem Domain
The area of the user’s business for whcih a system is being developed
Application
The portion of the new system that satisfies the user’s needs in the problem domain
Help Desk
Support staff to assist users with technical or processing problems with the new system.
System Development Methodology
Guidelines for completing every activity in the SDLC including models, tools, and techniques
Model
representation of an important aspect of the real world
abstraction
we abstract (seperate out) as aspect of particular importance to us.
Models of system components
- flowchart
- data flow diagram (DFD)
- entity-relationship diagram (ERD)
- structure chart
- Use case diagram
- Sequence Diagram
Models used to manage the development process
- Gantt chart
- Organizational hierarchy chart
- Financial analysis models - NPV, ROI
Tools
Software support that helps create models or other components required in the project
Includes:
- Project Management apps
- Drawing/graphics apps
- Word processor/text editor
- visual modeling tool
- Integrated development environment
- database management application
- reverse engineer tool
- code generator tool
Integrated Development Environments (IDE)
Tools that help programmers with a variety of programming tasks
Visual Modeling Tools
Tools that help the analyst create and verify important system models, often generating program code
Technique
Guidelines that help an analyst complete a system development activity or task
Includes:
- Stragegic Planning
- Project Management
- User Interviewing techniques
- Data Modeling
- Relational database design
- structured analysis
- Structured design
- Structured Programming
- Software testing
- Object oriented analysis and design tech
Traditional Approach to Sys Dev
includes variations based on techniques used to develop systems with structured and modular programming. often reffered to as Structured System Development
Structured Approach
System dev using structured analysis, design, and programming techniques
Structured Program
program or prog module that has one beginning and one ending . Each step in the program execution consists of:
- Sequence of program statements
- Decision where one set of statements or another set of statements executes
- repetition of a set of statements
Top Down Programming
dividing more complex programs into a hierarchy of program modules i.e. main line statement in php calling functions beneath
Structured Design
Technique providing guidelines for deciding what the set of programs should be, what each program should accomplish and how the programs should be organized into a hierarchy. i.e. the many different parts of a payroll sys.
Structure Chart
a graphical model showing the hierarchy of prgram modules from the structured design. visual representation of the payroll sys.
Program Modules
i.e. enter time cards module, get employee pay rates. Loosely coupled means each module is as independant of the other mods as possible.
highly cohesive
each module accomplishes one clear task
Structured Analysis
technique used to define what processing the system needs to do, what data it needs to store and use, and what inputs and outputs are needed
data flow diagram DFD
strucutred analysis model showing the inputs, processes, storage, and outputs of a system. i.e. university course diagram in book
Entity-relationship diagram ERD
structured analysis and information engineering model of the data needed by a system. i.e. customer 1 - zero to many orders - 1 order to 1-many order items. (relationship view in access)
Information Engineering
Traditional system development methodology thought to be more rigorous and complete than the structured approach because of its focus on strategic planning, data modeling, and automated tools
OBJECT ORIENTED APPROACH
An approach to Sys Dev that views an info sys as a collection of interacting objects that work together to accomplish tasks
Object
thing in the computer system that can respond to messages
Object-oriented analysis OOA
Defining all types of object that work in the system and showing what user interactions, called use cases are required to complete tasks
Object-oriented design OOD
defines all of the additional tyupes of objected necessary to communicate with people and devices in the system, shows how the objects interact to complete tasks, and refines the definition of each to of object so it can be implemented with a specific language or environment
Object-oriented Programming OOP
Writing statements in a programming language to define what each type of object does, including the messages that the objects send to each other
Class diagram
a graphical model used in the object oriented approache to show classes of objects in the system. i.e. customer/account/savings acct/checking acct diagram Shows one to many as well as hiarchy
TREND - UP Process
Object oriented system development methodology offered by IBM’s Rational Software
TREND - Extreme Programming XP
Sys dev approach that adapts techniques from many sources and add some new ideas. “lightweight” system methodology - keep it simple and efficient.
TREND - SCRUM
The video from class. refers to rugby’s system for getting an out of play ball back into play. Similarities between the sport and sys dev app. Both quick adaptive and self organizing.
Repository
database that stors info about the system in visual modeling tool including models, descriptions and references that link the models together.
