Acc 261 Exam #2

Definition: Figuring out what’s really going on: The problems, the needs, the requirements of the new system
Characteristics: Impertinence, Impartiality, Relaxing constraints, Attention to details, Reframing

Traditional: Interviewing individuals, Interviewing groups, Observing workers, Studying business documents
Contemporary:
Joint Application Design (JAD)
Brings together key users, managers, and systems analysts
Purpose: collect system requirements simultaneously from key people
Conducted off-site
Intensive group-oriented requirements determination technique
Team members meet in isolation for an extended period of time
Highly focused
Resource intensive
Started by IBM in 1970s
JAD Participants
Session Leader: facilitates group process
Users: active, speaking participants
Managers: active, speaking participants
Sponsor: high-level champion, limited participation
Systems Analysts: should mostly listen
Scribe: record session activities
IS Staff: should mostly listen

Group Support Systems
• Facilitate sharing of ideas and voicing of opinions about system requirements

CASE tools
Software used to analyze existing systems
Help discover requirements to meet changing business conditions
System prototypes
Iterative development process
Rudimentary working version of system is built
Refine understanding of system requirements in concrete terms

Prototyping: (Types: Evolutionary and Throwaway)
Quickly converts requirements to working version of system
Once the user sees requirements converted to system, will ask for modifications or will generate additional requests
Most useful when:
◦ User requests are not clear
◦ Few users are involved in the system
◦ Designs are complex and require concrete form
◦ History of communication problems between analysts and users
Tools are readily available to build prototype
Drawbacks of prototyping:
Tendency to avoid formal documentation
Difficult to adapt to more general user audience
Sharing data with other systems is often not considered
Systems Development Life Cycle (SDLC) checks are often bypassed
Throwaway prototypes are hard to throwaway

Search for and implementation of radical change in business processes to achieve breakthrough improvements in products and services
 Goals
◦ Reorganize complete flow of data in major sections of an organization
◦ Eliminate unnecessary steps


 Goals (cont.)
◦ Combine steps
◦ Become more responsive to future change
 Identification of processes to reengineer
◦ Key business processes
 Set of activities designed to produce specific output for a particular customer or market
 Focused on customers and outcome
 Same techniques are used as were used for requirements determination

 Gather group of programmers, analysts, users, testers, facilitator
 Document complaints of current system
 Determine important user roles
 Determine, prioritize, and describe tasks for each user role
 Group similar tasks into interaction contexts
 Associate each interaction context with a user interface for the system, and prototype the interaction context
 Step through and modify the prototype

-see picture on study guide-

Context Diagram
A data flow diagram (DFD) of the scope of an organizational system that shows the system boundaries, external entities that interact with the system and the major information flows between the entities and the system
Does not contain data store

Level-0 Diagram
A data flow diagram (DFD) that represents a system’s major processes, data flows and data stores at a high level of detail

Level-X Diagram
Breaks down each process in Level-0 into smaller processes
Ex: Process 1.0 in Level-0 gets broken down into smaller processes in the Level-1 diagram

Process with only outputs

Process with only inputs

Show top-down functional decomposition or structure of a system
Provide outline for drawing DFDs

The conservation of inputs and outputs to a data flow process when that process is decomposed to a lower level
Balanced means:
Number of inputs to lower level DFD equals number of inputs to associated process of higher-level DFD
Number of outputs to lower level DFD equals number of outputs to associated process of higher-level DFD

Logical DFDs state what the new system will do (“Business View”)
The same rules pertaining to balance and decomposition apply

Physical DFDs show implementation details and explain how the final system will work. (“systems (programmer) view”)
References to actual technology
Format of information moving through process
Human interaction that is involved

Process labels identify technology (people or systems) used to process the data.
Data flows and data stores identify actual name of the physical media.

Physical aspects of system are removed as much as possible.
Current system is reduced to data and processes that transform them.

Includes additional functions
Obsolete functions are removed
Inefficient data flows are reorganized

Represents the physical implementation of the new system