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REQUIREMENT ANALYSISUNIT - II
REQUIREMENT ANALYSIS PROCESS
process of determining the needs or conditions to meet for a new or altered product.
Figure shows the requirements analysis process:
In involves [5] steps: Gather and list requirements Develop service metrics Characterize behavior Develop requirements Map requirements
Metrics – measurements | behavior - range of actions
Develop service matrics
Characterize
behavior
Develop Rqrmnts
Map Rqrmnts
Gather & List
rqrmnts
GATHERING AND LISTING REQUIREMENTS
Communicate with the users to gather their requirements.
Service requirements are gathered and developed with initial conditions on the architecture and design, with input from users, administration and management.
Then refined(process of purification/ unwanted requirements removed) by applying our experience and knowledge about the analysis process.
DETERMINING INITIAL CONDITIONS
It is the starting of the analysis process. Initial conditions consist of
Type of network project Scope/ Future of the architecture and
design( Project Scope and Product Scope) Initial architecture/ design goals.
Part of the initial conditions of new networkproject may be determining its performancetarget: multi-tier performance or single-tierperformance.
DETERMINING INITIAL CONDITIONS
Type of Network Project: New Network Modification of an Existing network
Scope/Future of Network Project: Network size Number of sites Analysis of network problems Outsourcing : across multiple vendors. Consolidation : facilitate ability to pursue
financings for working capital. Upgrade: replacing a product with a newer
version.
DETERMINING INITIAL CONDITIONS
Initial Architecture / Design Goals: Upgrade technology/ vendor Improve performance to part / All of network Support new users, applications or devices Solve perceived(existing) problems within
system Increase security Support a new capability in system.
DETERMINING INITIAL CONDITIONS
Common constrains(activity) on a network project include Funding limitations Organizational rules and regulations Time and schedule limitations Technical constrains for existing users ,
applications, devices, networks and management.
performance target: Single tier performance Multi tier performance
SINGLE TIER VS MULTI TIER PERFORMANCE
Do not have a set of applications & users.
There is no threshold between low and high performance requirements.
Have a set of applications & users.
There is a threshold between low and high performance requirements.
SETTING CUSTOMER EXPECTATIONS
It is important to begin to set customer expectations. This consists of:a rapid(happening in a short time), initial evaluation(estimation) of the problem, andestimating resources and schedule.
The intent is to inform customers, early in theprocess, when their expectations are not realistic.
WORKING WITH USER
There are some successful techniques thatcan be used: developing a survey to email, FAX, or mail to
users. following up on the survey with one-on-one
telephone calls or conference calls. following up calls with face-to-face meetings
with selected individuals or groups. whiteboard sessions to elicit ideas from users. spending time with users while they work.
TAKING PERFORMANCE MEASUREMENTS
It is helpful to measure performance levels ofapplications and devices that will be used inthe planned network.
Either by testing applications and devices ona separate, controlled network (e.g., testbednetwork) or by measuring their performancelevels on the existing network.
Measurements of peak application and device performance can be used to determine how much degradation in performance is experienced on the existing network.
It become a validation of performance problems on the existing network.
Capture all of the traffic from an application session, by characterized monitoring of the network.
TRACKING AND MANAGING REQUIREMENTS
Requirements also need to be tracked(rough path) and managed.
A listing of requirements should be kept up to date, in a location where everyone involved in the process has access them.
Web is a great tool for posting, tracking and managing requirements.
Number of methods used to track and manage requirements.
TYPES OF MANAGING REQUIREMENTS
Two ways: Paragraph form Tabular form
Paragraph form: Where a requirement is changed within its
original paragraph.
Tabular form: Other software tools can be used for this
process, such as databases and spreadsheets. the key point is requirements documents should
be living documents, updated on a regular basis.
ID/NAME DATE TYPE DESCRIPTION
USER’S
REQUIREMENTS
26 -SEP-2014 ORIGINAL Technology based
upgrades
27 -SEP-2014 CHANGE Software based
upgrades.
28 -SEP-2014 DELETE topology based
upgrades.
(LAN,WAN,MAN)
MAPPING LOCATION INFORMATION
MAPPING LOCATION INFORMATION
The locations of applications and devices will be mapped to show their relative physical locations.
When gathering requirements, note the locations of servers and specialized devices and where specific applications are being used.
Shows an example of how this is done with a Metropolitan-Area Environment with devices and applications.
THANK YOU
DEVELOPING SERVICE METRICS
RMA CAPACITY DELAY
FRAME RELAY UPTIME DOWNTIME PACKET LOSS RATIO PACKET ERROR RATE BIT ERROR RATE
MEASUREMENT TOOLS Where to apply service metrics
CHARACTERIZING BEHAVIOR
Estimates of user session duration The number of active sessions Data sizes Complex / detailed models of user
application behaviour.
MODELLING AND SIMULATION
Equipment type Placement Configuration Behavior under stress / failure.
USER BEHAVIOUR
User work-time and durations Each application the total number of users. Duration of activity
APPLICATION BEHAVIOR
Characterizing application behaviour Data sizes that the application will be
processing Passing across the network Frequency and time duration. Flow directions(client to server) Requirements for multicasting/broadcasting.
DEVELOPING RMA REQUIREMENTS
Reliability Maintainabiliy Availability.
Monthly / weekly / yearly:
Uptime (how to measure) Downtime (how to measure)
DEVELOPING CAPACITY REQUIREMENTS
Capacity: Estimating data rates
Peak data rate(PDA) Minimum data rate(MDR)
DEVELOPING SUPPLEMENTAL PERFORMANCE REQUIREMENTS
Operational suitability (operation/support) Supportability Confidence
RMA
TOOLS
REPAIR AND SPARE PARTS
REQUIREMENT MAPPING