Quiz 1 (REDO) System Requirements Specification Flashcards
The Heart of the process
Analysis
Several tools of structured analysis:
- Data Flow Diagram
- Data Dictionary
- Structured English
- Decision Trees
- Decision Tables
Is about understanding the situations, not solving the problems.
System Analysis
Effective analyst therefor emphasize imvestigation and questioning to learn how a system currently operates and to identify the requirements user have for a new or modified one.
Systen Analysis
Involves studying the current business system to find out how it works and where improvement should be made.
Requirement Determination
Is a feature that must be included in the new system. It may include the way of capturing or processing data, producing information, controlling a business activity, or supporting management.
Requirements
Three Major Activities of Requirement determination:
- Requirement Anticipation
- Requirement Investigation
- Requirement Specification
Involves using past experience in a specific business area or similar environments to influence a system analyst’s study. This can help foresee potential problems or features needed for a nee system.
Requirement anticipation
This activity is at the heart of system analysis.
Requirement investigation
It involves the using various tools and skills used by analysts to study the current system and document its features for further analysis
Requirement investigation
It relies on fact-finding techniques and includes methods for documenting and describing system features
Requirement investigation
The data produce during fact-finding investigation are analyzed to determine requirements specification and the description of features for a new system.
Requirement Specification
Requirement Specification:
Three interrelated parts:
- Analysis of Factual data
- identification of essential requirements
- Selection of requirements fulfillment strategies.
The data collected during fact-finding study and included in data flow and decision analysis documentation are examined to determine how well the system is performing and whether it will meet the organization’s demands.
Analysis of factual data
Features that must be included in a new system, ranging from operational details to performancd criteria, are specified.
Identification of essential requirements
The method will be used to achieve a stated requirements are selected. These form the basis for system design, which follows requirement specifications.
Selection of requirement fulfillment strategies.
- Begin with the basics
- Analyst must raise questions that, when answered, will provide a background of fundamental details about the system and describe it.
Understand the Process
-Analyst needs to find out what data are used to perform each activity.
-Most Business transaction also produce information
Identify data used and information produced
-Frequency of business activities varies greatly.
-therefore, analyst should learn how often the activity is repeated
Determine process timing and volume
The weak or missing control area is an important discovery in any system investigation.
Identify control
User Transaction Requirements;
TPS System:
Capture - Process - Store Data (for a reason)
- Decision unlike transaction activities, may not follow a specific procedure.
- Decision systems may focus on the past, the present or the future.
User Decision Requirements
It refers to the specific methods analysts use for collecting data about requirements.
Fact-Finding techniques
Fact-finding techniques (4)
- Interview
- Questionnaire
- Record inspection (on site review)
- Observation
Analyst use “_____________” to collect information from individuals or groups. The respondent are generally current users of the existing system or potential users of the proposed system.
Interview
The use of “_______________” allows analyst to collect information various aspect of a system from a large number of persons.
Questionnaire
In “_____________”, analyst examine information that has been recorded about the system and user.
Record Review
Allows analyst to gain information they cannot obtain by other fact-finding methods. Through “____________”, analyst can examine first hand information about how activities are carried out.
Observation
This method is most useful when analysts need to actually observe how documents are handled.
Observation
Is a set of techniques and graphical tools that allows the analyst to develop a new kind of system specification that are easily understandable to the user.
Structure analysis
Considers new goals and structured tools for analysis
Structure analysis
Structured Analysis Attributes.
- It is graphic
- It is logical rather than physical
also known as “bubble chart,” has the purpose of clarifying system requirements and identifying major transformation that will come from programs in system design.
Data Flow Diagram
It is the starting point of the design phase.
Data Flow Diagram
Common symbols of DFD:
- External Entities
- Processes
- Data Flows
- Data Stores
Type of DFD:
are represented by squares as the sources or destination of data.
External Entities
Type of DFD:
Are represented by rectangles with rounded corners.
Processes
Type of DFD:
are referred by arrows to denote the physical or electronic flow of data.
Data Flows
Type of DFD:
are physical or electronic-like XML files denoted by open-ended rectangles
Data Stores
It is a structure repository of metadata that provides a comprehensive description of data used.
Data Dictionary
Its main purpose is to provide a common language and understanding of the data.
Data Dictionary
Components of a data dictionary:
- Data Element Name
- Data Type
- Domain Value
- Definition/Description
- Source
- Date Created
It is a technique used by analyst to model and document the logic of information processes.
Structure English
Is hierarchical model used in data analysis and decision-making. It visually represents a decision making process by mapping out possible outcomes based on different choices.
Decision Tree
It is diagram that presents conditions and actions sequentially and thus shows conditions to consider first, which second and so on. It is also a method of showing the relationship between conditions
Decision Tree
Are concise visual representations used to specify which action is performed based on given conditions.
Decision tables
They serve as algorithm that produce a set of actions. You can think of them as a structured way to model decision making.
Decision table
