System Design Chapter 04 Flashcards
Analysis Activities
Gather info - Define Sys Req - Prioritize Requirements - Prototype for Feasibility & discovery - Generate & evaluation alternatives - Review recommendations with Management
Gathering Info
interviewing users - watching users - review planning docs - review policy statements - study documentation from existing system
Define System Requirements
Uses modeling to help define system requirements
Logical Model
Any model that shows what the system is required to do without committing to any one technology
Physical Model
Any model that shows how the system will actually be implemented
Scope Creep
system requirements tend to expand as users make more suggestions
Prioritize Requirements
Identify the most essential requirements of the new system
Prototype for Feasibility and Discovery
used to better understand the user’s needs. Checks the feasibility of certain approaches to the business need.
Generate and Evaluate Alternatives
Many alternatives exist that will need to be evaluated for the best match
Review Recommendations with Management
When all other analysis activities are complete the review with management will happen to decide if best to proceed or not
System Requirements
Specifications that define the functions to be provided by the system
Functional Requirements
a system requirement that describes and activity or process that the system must perform
Non-functional requirement
other than activities -such as technology-performance - usability - reliability and security
Non-func req: Technical Requirement
describes an operational characteristic related to an org’s environment - hardware - and software
Non-func req: Performance Requirement
describes an operational characteristic related to workload measures such as throughput and response time.
non-func req: Usability Requirement
describes an operational characteristic related to users - such as the user interface - work procedures - online help and documentation
non-func req: Security requirement
describes users access to certain functions and the conditions under which access is granted.
Models
representation of some aspect of the system being built
Mathematical Model
series of formulas that describe technical aspects of a system.
Descriptive Models
narrative memos - reports or lists that describe some aspect of a system.
Graphical Model
diagrams and schematic representations of some aspect of a system
Stakeholders
all the people who have an interest in the success of a new system the users the clients (paying for it) the technical staff
Horizontal user needs
Info flow across multiple departments
Vertical user needs
clerical - middle management and senior executives
transaction
single occurrence of a piece of work or activity done in an organization
business users
uses the system to perform day to day operations
Information users
pulls info form the system on a daily - weekly - monthly and annual schedule - may not have access to edit info
Management users
pulls statistics and summary info from the system..
Executive users
more interested in strategic issues as well as daily issues
External users
customers may access through internet. Suppliers may have access to check inventory and initiate billing.
Client Stakeholders
Sometimes same as the executive users. May also be separate. In charge of the money
Technical Stakeholders
maintain - support and provide guidance for the system
Information Gathering Techniques-old style
learned existing system - extracted the logical functions - converted to new system - defined the new system - also called pave the cow paths as they basically just automate the old system
Information Gathering Techniques-new style
goal is to develop a set of logical system requirements for the new system immediately while sometimes referring to the old sys
Question Themes
What are the business operation sand processes (to user - what do you do) - How should those operations be performed? (to user how do you do it - what steps do you follow) - What information is needed to perform those operations (to user: what information do you use - what forms or reports do you use)
Effective Interviews
Prepare for interview - conduct the interview - follow-up the interview
Preparing for Interview
Determine Objective - Decide on what users to attend - Prepare detailed questions - Make final interview arrangements and communicate to all participants
Conducting the Interview
Dress/time arrival - limit the time of interview - look for exception and error conditions - i.e. what ifs - take detailed notes
Follow up the interview
process the info from the interview and return to interviewees to confirm the information.
Observing
observing the business processes in action will help you understand the business function. Can include walk throughs or doing the task yourself
Workflow
is a sequence of processing steps that completely handles one business transaction or customer request.
Activity Diagram
type of workflow diagram that describes the user activities and their sequential flow
Synchronization Bar
A symbol in an activity diagram to control the splitting or uniting of sequential paths
Swimlane
a rectangular area on an activity diagram representing the activities of a single agent.
Prototype
a preliminary working model of a larger system
Mock-up
an example of a final product that is for viewing only and is not executable.
Joint Application Design sessions or JAD
technique to define requirements or design a system in a single session by having all necessary people participate
Group support system GSS
computer sys that allows multiple people to participate with comments at the same time from their own computer
Research Vendor Solutions
Technical specifications - a demo or trial system - references of existing clients who might allow you to view their system - on site visit - print out of screens and reports
Structured Walkthrough to validate info
review of the findings from your investigation and of the models built based on those findings.
