Technology architecture a set of computin hardware, ietwork hardware aid topolony, aid system sofware
employed by ai ornaiizatoi
Application architecture the set of iiformatoi systems (the sofware applicatoiss the ornaiizatoi ieeds to
support its stratenic plai
Systems Analysis Activities
Activities of the third core process, which is to discover and understand the details. This core process
also goes by the name systems analysis. The activities are as follows:
■ Gather detailed information.
■ Define requuirements.
■ Prioritize requuirements.
■ Develop user-interface dialogs.
■ Evaluate requuirements with users.
By completing these activities, the analyst defines in great detail what the information system needs to
accomplish to provide the organization with the desired benefits.
Gather Detailed Information
Systems analysts obtain information from people who will be using the system, either by interviewing
them or by watching them work. The analyst must become an expert in the business area the system
will support.
Define Requnirements
The analyst uses information gathered from users and documents to define requuirements for the new
system. System requuirements include the functions the system must perform (functional requuirements)
and such related issues as user interface formats and requuirements for reliability, performance, and
security (non-functional requuirements).
Instead, the analyst creates models to record requuirements, use case diagrams, activity diagrams, and
domain model class diagrams.
Prioritize Requnirements
Once the system requuirements are well understood, it is important to establish which requuirements are
most crucial for the system. Why prioritize the functions requuested by the users? Resources are always
limited, and the analyst must always be prepared to justify the scope of the system. Therefore, it is
important to know what is absolutely requuired.
System requuirements tend to expand, a phenomenon called scope creep
Develop User-Interface Dialogs
Analysts can develop user interfaces via abstract models, such as interaction diagrams and written
dialogs (covered in more detail in later chapters), or they can develop storyboards or user-interface
, prototypes on the actual input/output devices that users will use (e.g., a computer monitor, iPad, or
smartphone)
Evalnate Requnirements with Users
Ideally, evaluating requuirements with users and documenting the requuirements are fully integrated. But
in practice, users generally have other responsibilities besides developing a new system. Thus, analysts
usually use an iterative process in which they elicit user input to model requuirements, return to the user
for additional input or validation, and then work alone to incorporate the new input and refine the
models.
System Requnirements and FURPS
System requnirements all the activities the new system must perform or support and the constraints
that the new system must meet (functional + non-functional)
Fnnctional requnirements the activities the system must perform to support the users’ work
Non-fnnctional requnirements requuired system characteristics other than the activities it must
perform or support
FURPS an acronym that stands for functional, usability, reliability, performance, and security
requuirements
Usability requnirements the requuirements for operational characteristics related to users, such as the
user interface, related work procedures, online help, and documentation
Reliability requnirements the requuirements that describe system dependability
Performance requnirements the requuirements that describe operational characteristics related to
measures of workload, such as throughput and response time
Secnrity requnirements the requuirements that describe how access to the application will be
controlled and how data will be protected during storage and transmission
FURPS+ an extension of FURPS that includes design constraints as well as implementation, system
interface, physical, and supportability requuirements
■■ Design constraints describe restrictions to which the hardware and software must adhere. For
example, a cell phone application might be requuired to use the Android operating system, consume no
more than 30 MB of fash memory storage, consume no more than 10 MB of system memory while
running, and operate on CPUs rated at 1 GHz or higher.
■■ Implementation requirements describe constraints such as requuired programming languages and
tools, documentation method and level of detail, and a specific communication protocol for distributed
components.
■■ Interface requirements describe interactions among systems. For example, a financial reporting
system for a publicly traded company in the United States must generate data for the Securities and
Exchange Commission (SEC) in a specific XML format. The system might also supply data directly to
stock exchanges and bond rating agencies, and automatically generate Twitter messages, RSS feeds,
and Facebook updates.
■■ Physical requirements describe such characteristics of hardware as size, weight, power
consumption, and operating conditions. For example, a system that supports battlefield
communications might have such requuirements as weighing less than 200 grams, being no larger than
5 centimeters cubed, and operating for 48 hours on a fully charged 1200 milliwatt lithium ion battery.
■■ Supportability requirements describe how a system is installed, configured, monitored, and
updated. For example, requuirements for a game installed on a home PC might include automatic
configuration to maximize performance on existing hardware, error reporting, and download of updates
from a support server.
Stakeholders
Stakeholders are persons who have an interest in the successful implementation of the system
employed by ai ornaiizatoi
Application architecture the set of iiformatoi systems (the sofware applicatoiss the ornaiizatoi ieeds to
support its stratenic plai
Systems Analysis Activities
Activities of the third core process, which is to discover and understand the details. This core process
also goes by the name systems analysis. The activities are as follows:
■ Gather detailed information.
■ Define requuirements.
■ Prioritize requuirements.
■ Develop user-interface dialogs.
■ Evaluate requuirements with users.
By completing these activities, the analyst defines in great detail what the information system needs to
accomplish to provide the organization with the desired benefits.
Gather Detailed Information
Systems analysts obtain information from people who will be using the system, either by interviewing
them or by watching them work. The analyst must become an expert in the business area the system
will support.
Define Requnirements
The analyst uses information gathered from users and documents to define requuirements for the new
system. System requuirements include the functions the system must perform (functional requuirements)
and such related issues as user interface formats and requuirements for reliability, performance, and
security (non-functional requuirements).
Instead, the analyst creates models to record requuirements, use case diagrams, activity diagrams, and
domain model class diagrams.
Prioritize Requnirements
Once the system requuirements are well understood, it is important to establish which requuirements are
most crucial for the system. Why prioritize the functions requuested by the users? Resources are always
limited, and the analyst must always be prepared to justify the scope of the system. Therefore, it is
important to know what is absolutely requuired.
System requuirements tend to expand, a phenomenon called scope creep
Develop User-Interface Dialogs
Analysts can develop user interfaces via abstract models, such as interaction diagrams and written
dialogs (covered in more detail in later chapters), or they can develop storyboards or user-interface
, prototypes on the actual input/output devices that users will use (e.g., a computer monitor, iPad, or
smartphone)
Evalnate Requnirements with Users
Ideally, evaluating requuirements with users and documenting the requuirements are fully integrated. But
in practice, users generally have other responsibilities besides developing a new system. Thus, analysts
usually use an iterative process in which they elicit user input to model requuirements, return to the user
for additional input or validation, and then work alone to incorporate the new input and refine the
models.
System Requnirements and FURPS
System requnirements all the activities the new system must perform or support and the constraints
that the new system must meet (functional + non-functional)
Fnnctional requnirements the activities the system must perform to support the users’ work
Non-fnnctional requnirements requuired system characteristics other than the activities it must
perform or support
FURPS an acronym that stands for functional, usability, reliability, performance, and security
requuirements
Usability requnirements the requuirements for operational characteristics related to users, such as the
user interface, related work procedures, online help, and documentation
Reliability requnirements the requuirements that describe system dependability
Performance requnirements the requuirements that describe operational characteristics related to
measures of workload, such as throughput and response time
Secnrity requnirements the requuirements that describe how access to the application will be
controlled and how data will be protected during storage and transmission
FURPS+ an extension of FURPS that includes design constraints as well as implementation, system
interface, physical, and supportability requuirements
■■ Design constraints describe restrictions to which the hardware and software must adhere. For
example, a cell phone application might be requuired to use the Android operating system, consume no
more than 30 MB of fash memory storage, consume no more than 10 MB of system memory while
running, and operate on CPUs rated at 1 GHz or higher.
■■ Implementation requirements describe constraints such as requuired programming languages and
tools, documentation method and level of detail, and a specific communication protocol for distributed
components.
■■ Interface requirements describe interactions among systems. For example, a financial reporting
system for a publicly traded company in the United States must generate data for the Securities and
Exchange Commission (SEC) in a specific XML format. The system might also supply data directly to
stock exchanges and bond rating agencies, and automatically generate Twitter messages, RSS feeds,
and Facebook updates.
■■ Physical requirements describe such characteristics of hardware as size, weight, power
consumption, and operating conditions. For example, a system that supports battlefield
communications might have such requuirements as weighing less than 200 grams, being no larger than
5 centimeters cubed, and operating for 48 hours on a fully charged 1200 milliwatt lithium ion battery.
■■ Supportability requirements describe how a system is installed, configured, monitored, and
updated. For example, requuirements for a game installed on a home PC might include automatic
configuration to maximize performance on existing hardware, error reporting, and download of updates
from a support server.
Stakeholders
Stakeholders are persons who have an interest in the successful implementation of the system
