Applied Systems Analysis Fall 2003

1
Applied Systems AnalysisFall 2003
Class Notes 2

• Douglas Low
• [phone] (work) 2 min question
• [phone] (home) 5 min question
• [phone] (Lemoyne mailbox) leave message

2
Session 2

• Handout Project Assignment
• Discuss Reading Assignment
• Discuss Homework
• Introduce Requirements Table
• Next homework
• UML - Use cases
• ROSE UML Exercise

3

• Homework Examples

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Homework Example
My wife shall have at least two childeren.
My wife shall be faithful.
My wife shall be under five foot eight.
My wife shall be educated with a college degree.
My wife shall vacum once a week.
My wife shall dust the house once a week.
My wife shall have a job if she wants.
My wife shall be a brunet.
My wife shall have a career before we marry.
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Homework Example 2

• Shall be intelligent.
• Must have college degree.
• Shall be good looking.
• Panel of 10 friends will determine.
• Shall be self sufficient.
• Must have lived alone before and done everything
  for herself. (ie. Dishes, laundry, cleaning,
  etc.)
• Shall be personable.
• Will be required to have dinner with just my
  parents and they will determine.
• Shall be from a good family.
• Must have job and house and be polite and
  personable.
• Shall show me genuine love.
• Thats for me to test and figure out.

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Homework Example 3

• My wife shall have a net income of 100,000
  dollars for at least 20 years.
• My wife shall be outgoing enough to not be afraid
  to make a scene in public.
• My wife shall be smart enough to play chess.
• My wife shall be so beautiful that a modeling
  agency would hire her on the spot.
• My wife shall have graduated from a creditable
  institution.
• My wife shall be able to cook my favorite dinner.
  
• My favorite dinner shall be delicious and
  editable.
• My wife shall be a woman from head to toe
• My wife shall have a 34C brawl size.
• My wife shall be able to hold a conversation
  longer than 10 minutes.

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Homework example 4

• Set of Requirements for Spouse of My Dreams 
• The spouse of my dreams shall believe in a
  greater being, such as God.
• The spouse of my dreams should be Catholic with a
  strong faith in their religion.
• The spouse of my dreams should love me for who I
  am.
• The spouse of my dreams will share
  responsibilities within the relationship.
• The spouse of my dreams should respect me.
• The spouse of my dreams should be able to
  communicate effectively.
• The spouse of my dreams will have a good sense of
  humor.
• The spouse of my dreams shall want to have
  children.
• The spouse of my dreams should be motivated.
• The spouse of my dreams shall be able to take
  initiative.
• The spouse of my dreams shall be able to be
  honest.
• The spouse of my dreams should be independent.

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Homework Example 5

•  
• My husband will be male. Test Inspect
• My husband shall be taller than myself, at least
  510. Test Inspect by measuring
• My husband shall hold at least a bachelors
  degree. Test analyze a diploma
• He shall be able to do wash clothes. Test
  Demonstrate
• He shall be able to fold clothes. Test
  demonstrate
• Shall be able to iron. Test demonstrate
• He shall be a non-smoker. Test analyze him
• He shall be able to change the oil on a car.
  Test demonstrate
• He shall be older than myself. Test  Inspect
  birth certificate
• He will have all his teeth. Test inspect
  teeth
• He shall not have a beard. Test inspect
  visual appearance
• He shall not have a mustache. Test inspect
  visual appearance
• He shall be employed. Test inspect proof of
  employment
• He shall be drug free. Test analyze drug
  test
• He shall not be a criminal. Test inspect
  criminal record
• He shall not be poor. Test analyze bank
  statements
• He shall not be bald. Test inspect the head
  for hair
• He shall be able to make a bed. Test
  demonstrate

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Requirements Table

• Requirement
• Type
• Requirement Text
• Verification Method
• If test then What use case is associated
• Priority
• Source

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Is each Requirement Verifiable

• Subjective requirements are not verifiable
• Look for words like Maximize, minimize, support,
  adequate, but not limited to, user friendly,
  easy, sufficient
• Determine how each requirements will be verified
  as it is written
• test, shall be .3 seconds
• demonstrate, shall be capable of simultaneous
  viewing
• analyze, MTBF shall be 1 day
• Inspect, shall be green

Subjective Requirements from the customer must be
converted into achievable and agreed to
Requirements
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Requirement Database Types

• All Requirements are defined in the requirements
  database as one and only one of the following
  types
• Ø      Functional shall automatically track
  airborne targets
• Ø      Performance shall discriminate targets
  within 3 minutes
• Ø      Capacity shall maintain 300 tracks in
  the
• Ø      Constraint including cost, specific
  equipment, legacy components etc.
• Ø      Reliability MTBF shall be 100 days
• Ø      Interface shall use RS-232 interface
  to
• Ø      Test the system test shall stress the
  system
• Ø      Safety in accordance with SPCL-610
  and BI-431
• Ø      Data shall depict target range in
  meters

We should do this but we dont. It helps
Partition Requirements or place the requirement
in the proper document section.
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OO Process Steps
Ø      Define requirements Allocate and Derive
requirements Map requirements to use cases Map
requirements to classes Ø      Define use
cases Draw Diagrams     Write use case
summary Include requirements External
Interfaces Ø      Define domain model class
diagram Add attributes when known Ø      Review
requirements   Ø      Define use case scenarios
Include a summary Ø      Define first level
decomposition class diagram Take from domain
class diagram Include boundary objects,
controllers and entities Ø      Review
Preliminary Design  Ø     Create a sequence
diagram for each scenario Use only objects in
the class diagram Update scenario documentation
to include details Ø      Update class
diagram Add methods to classes when known
(Internal interfaces) Ø     Update Documentation
(interfaces etc.) Ø    Review Design
R
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UML

• Use Cases
• Model
• Inheritance
• Relationships
• Interaction
• Behavior
• Scenarios
• Stereotypes
• UML

• Packages
• Classes / objects
• Actors
• Diagrams
• State diagram
• Use Cases diagrams
• Sequence Diagrams
• Deployment diagram
• Class / Object diagram
• Methods / operations
• Hidden/private data

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Model

• Model Abstraction of a physical system with a
  certain purpose.
• Websters Model - (noun) a description or analogy
  used to help visualize something that cannot be
  directly observed.
• Websters Model - (verb) to produce a
  representation or simulation of.

We will model a software system using UML and
document the software model it in an SRS.
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Use Case Diagram
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Use Case - Definition
Do Something (Verb - Noun)

• Definition
• A use case is a sequence of actions within a
  system to achieve a particular goal for an actor.
• Describes system behavior from the outside - in.
• Represents a major piece of functionality that is
  complete from beginning to the end.
• A use case must deliver something of value to an
  actor.
• Use case name
• Stated from the user perspective as a
  present-tense verb phrase in an active voice.

• What does the actor want from the system?
• What notifications are required?
• What external events must be handled?
• What requirements go with the use case?

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Actors

• Actor represents an entity that interacts with
  the system under development (in our case CSCI)
• Name should be a role not a title.
• e.g.. Use Case Designer not Systems engineer
• Who uses the CSCI
• Who installs the CSCI
• Who maintains the CSCI
• Who starts and shuts down the CSCI
• What other system interface with this CSCI
• Where does the information go to
• What initiates events that invoke an action from
  the CSCI
• Could be person, external system, other CSCI of
  the present system, something physical like water
  or bullet

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Relationships

• Between classes
• Role
• Between Actors and Use Case
• Role between
• Between Use Cases
• ltltextendsgtgt ltltusesgtgt

These are fluffy I dont use them unless they
mean something to the design like an interface
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Perfect Wife (homework example)
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Includes and Extends
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Disclaimer

• The following system example is not supposed to
  be complete rigorous, possible or anything else
  good.
• The following system description is only for
  training purposes.

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Simple System
Start system
Operator
Create Gold
Store room
Rabbit Poop
Gold Creator System
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System Description Requirements

• The system shall automatically feed raw material
  from the input hopper and into the pre-processor.
• The system shall automatically feed preprocessed
  material from the pre processor into the
  processor.
• The automation shall be controlled by a computer
  system.
• The computer system shall control temperature,
  pressure and humidity in the pre-processing
  stage.
• The system shall control preprocessing parameters
  based on user defined input data.
• The system shall automatically control the level
  of sodium hydroxide solution in the processor.
• The system shall automatically drain and dry the
  mixture in the processor.
• The system shall control the processing based on
  user define input parameters.
• The system shall alert the operator when the
  batch is finished.
• The system shall diagnose problems in the system
  and isolate the fault down to an LRU.

• The system to be developed is a precious metal
  (PM) generator. It creates gold silver from the
  raw material rabbit poop.
• The entire process is automated including
  automatic feed of raw material into the
  processing mechanism and automatically feed
  finished material into a store room after the PM
  is created. The automation is controlled by a
  computer system computer software.
• The entire process is performed in batches.
• The process of creating PM requires
  preprocessing. During preprocessing the raw
  material is brought to a specified temperature
  and pressure and humidity and maintained within
  predefined limits for a predefined length of
  time.
• Processing of the preprocessed material includes
  several steps
• Dissolve the preprocess batch in a sodium
  hydroxide solution. Produce and maintain 100
  degrees F temperature. Wait for 1 hour
• Add 6 grains of a secret ingredient. Stir for 1
  minute.
• Solution is pumped through a filter and the
  effluent is disposed of to a city drain.
• The filter now contains PM. The Filter is dried
  using a forced air heater. The PM dust is
  collected from the filter through a funnel and
  onto the conveyer which is transferred to the
  store room via a conveyor belt.
• After the process is completed the system sounds
  a signal to indicate to the operator to provide
  more raw material.
• The system is self diagnosing and will provide
  the maintainers with the problem and solution.

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Simple System
Start system
Operator
Create PM
Store room
Rabbit Poop
Define parameters
Set up operator
Diagnose problems
Maintainer
Precious Metal (PM) Creator System
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Requirements to Usecase

• Create PM
• Create PM
• Create PM
• Create PM
• Create PM
• define user parameters
• Create PM
• Create PM
• Crete PM
• define user parameters
• Create PM

• The system shall automatically feed raw material
  from the input hopper and into the pre-processor.
• The system shall automatically feed preprocessed
  material from the pre processor into the
  processor.
• The automation shall be controlled by a computer
  system.
• The computer system shall control temperature,
  pressure and humidity in the pre-processing
  stage.
• The system shall control preprocessing parameters
  based on user defined input data.
• The system shall allow the operator to input and
  verify preprocessing parameters.
• The system shall automatically control the level
  of sodium hydroxide solution in the processor.
• The system shall automatically drain and dry the
  mixture in the processor.
• The system shall control the processing based on
  user define input parameters.
• The system shall allow the user to input and
  verify processing parameters.
• The system shall alert the operator when the
  batch is finished.
• The system shall diagnose problems in the system
  and isolate the fault down to an LRU.

All Requirements that are verified by TEST
have an associated Use Case
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Use Case Description

• 1 CSCI Capability 1 Infrastructure
• 1.1 Capability 1 Use Case 1 (Summary)
• 1.1.1 Preconditions
• 1.1.2 Post conditions
• 1.1.3 Primary flow of events
• 1.1.3.1 Sequence Diagrams
• 1.1.4 Alternate flow of events
• 1.1.4.1 Sequence Diagrams
• .1.1.5 Exception flow of events
• .1.5.1 Sequence Diagrams

Include Trigger
Include Trigger
Include Trigger

• 3.2.4.1.n Capability 1 Use Case n
• Use Case n Documentation Set 
•  
• 3.2.4.n CSCI Capability x ______________
• 3.2.4.x.m Capability n Use Case m

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Create Gold Main Flow Use Case Description

• Main Flow Summary
• This use case will make the owner of the system
  rich. The system will automatically take the raw
  materials from a hopper process it into gold then
  add the gold to the store room . The entire
  process is automatic and maintenance free. All
  you have to do is add material. The machine takes
  a full hopper of raw material to create one pound
  of final product.
• 3.2.4.1.1.1 Preconditions
• The system has been started and initialized and
  is running in idle state. The material hopper is
  full of raw material.
• 3.2.4.1.1.2 Post conditions
• Store room is increased by one pound of pure
  gold.
• 3.2.4.1.1.3 Primary flow of events
• The operator initiates the process by pressing
  the run button. The raw material is transferred
  to the preprocessor automatically by a conveyor
  mechanism. As the material is preprocessed the
  system keeps track of the amount of raw material
  is processes and display the value on the
  control panel along with the elapsed time. The
  preprocessor maintains temperature, pressure
  humidity and oxygen level for a time period. All
  of the parameters are adjustable (see use case
  Start System.
• As the material is preprocessed, it is
  transferred into the main processor by an
  automated conveyor.
• If any one of the parameters is out of
  specification by the predefined amount, and error
  report is generated and the use case is
  terminated.(E1).
• If no errors resulted from the preprocessing
  stage. The processor is automatically initiated
  after all of the raw material is preprocessed.
  The timer is initiated upon initiation of the
  processor.
• When a pre determined time as elapsed, the system
  automatically send the processed material to the
  store room via a material conveyer.This is the
  end of the use case
• 3.2.4.1.1.3.1 Sequence Diagrams
• 3.2.4.1.1.4 Alternate flow of events
• 3.2.4.1.1.4.1 Sequence Diagrams
• 3.2.4.1.1.5 Exception flow of events
• 3.2.4.1.1.5.1 Sequence Diagrams

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Homework 2 due Sept 15 1200 Noon

• Dream Spouse SOW
• Updated
• Dream Spouse Requirements
• Updated
• Placed in a Requirements Table
• Prioritized (High, Med. Low)
• Verification method assigned
• Project Draft (Cover Letter, Introduction,
  Problem Definition)
• Read Boggs Chapter 1