Workshop on Software Engineering Project

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Workshop on Software Engineering Project

• Lior Limonad
• limond_at_cs.bgu.ac.il
• www.cs.bgu.ac.il/wsep062
• Spring 2006
• Resource Applying UML and patterns 3ed
  Craig Larman

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Goal

• Acquire practical capabilities to deal with the
  process of an application construction
• Handle (changing) requirements
• From domain design to implementation
• Work in small teams (XP)
• Work by some customized process (UP)
• Control the implementation (TDD)
• Achieve a satisfactory solution (!)

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Method

• Through the whole semester period, work in small
  supervised teams to construct all artifacts (and
  implementation) of an evolving software
  application
• Customized process
• Mainly UP as illustrated in Applying UML and
  patterns 3ed, Craig Larman
• XP pair programming, TDD

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UP iterative and evolutionary

• Inception approximate vision, business case,
  scope, vague estimates
• Elaboration refined vision, iterative
  implementation of core architecture, resolution
  of risks, identification of most requirements
• Construction iterative implementation of
  remaining elements, preparation for deployment
• Transition beta tests, deployment

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Communications

• Analysis, Design and Implementation
• Requirements definition
• Structural definitions
• Behavioral definitions
• Systems external interactions definitions
• Teams interactions
• ? UML Just a diagramming notation standard. Not
  a method, process, or design guide.

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Technology

• Any current OO related
• Installed in Labs
• Supports enterprise architecture (layering)
• Versioning
• Support your decision!

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Case Study

• The Dito system (i.e. http//www.collective2.c
  om)A Trading systems support platform(No prior
  knowledge of investing is required!)
• A trading system (TS) is simply a group of
  specific rules, or parameters, that determine
  entry and exit points for a given equity. These
  points, known as signals, are often marked on a
  chart in real time and prompt the immediate
  execution of a trade. http//www.investopedia.com
  /university/tradingsystems/
• The Dito system is a software application that
  acts as a container platform for handling a
  collection of trading systems

dito to enrich, make wealthy.
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Dito system spec. cont.

• The stakeholders
• The equity market / stock market
• Stream input feed for TS analysis
• TS owners
• Introducing new signals activity
• Monitoring subscribers activity (income from
  subs.)
• TS subscribers
• View TS public activity summarizations
• Getting signals notifications (fax, email, sms)

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Dito system spec. cont.

• Definitions
• TS - Within the dito system, a TS is simply a
  stream of signals
• Signal may be either one of four conditioned
  trading hints
• Buy to open (BTO)
• Sell to close (STC)
• Sell short (SSH)
• Buy to close (BTC)

STC
SSH
BTC
BTO
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Dito system spec. cont.

• Signal attributes
• Type BTO, STC, SSH, BTC
• Amount ?
• Equity ID
• Limit upper bound for buying / lower bound for
  selling
• Stop upper bound for selling / lower bound for
  buying
• Execution precondition defines a set of
  correlated signals that must be executed first
• Validity Day, GTC (Good till cancel)

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Inception (One week)

• Initial short step to establish a common vision
  and basic scope for the project.
• Includes 10 of use cases
• Analysis of critical requirement
• Preparation of the development environment

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Use Case Diagrams
Warning Dont spend much time on
diagramming. Use case work means to write text,
not draw diagrams
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Use Cases

• Use cases are one way to capture (especially)
  functional requirements.
• They are stories of using a system to fulfill a
  goal.
• More formally, a use case is a collection of
  success and failure scenarios describing a
  primary actor using a system to support a goal.

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Use Cases cont.

• There is nothing object-oriented about use cases.
  
• So, why bother in an OOA/D workshop?
• We need some kind of requirements input for the
  design steps.
• They are common/popular.
• There is a UML-related topic.
• Use case diagrams

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Use Cases example

• Use Case UC1 Rent Video
• Level User-level goal (EBP level)
•  
• Primary Actor Clerk
• Preconditions
• Clerk is identified and authenticated.
• Stakeholders and their Interests
• Clerk Wants accurate, fast entry.
• Customer Wants videos, and fast service with
  minimal effort.
• Accountant Wants to accurately record
  transactions.
• Marketing Wants to track customer habits.
• . . .

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Use Cases example

• Main Success Scenario (or Basic Flow or Happy
  Path)
• Customer arrives at a checkout with videos or
  games to rent.
• Clerk enters Customer ID.
• Clerk enters rental identifier.
• System records rental line item and presents item
  description.
• (Clerk repeats steps 3-4 until indicates done.)
• System displays total.
• Customer pays. System handles payment.
• Clerk requests rental report.
• System outputs it. Clerk gives it to Customer.
• Customer leaves with rentals and report.

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Use Cases example

• Extensions (or Alternatives)
• a. At any time, System fails
• Clerk restarts System
• logs in
• requests recovery from prior state
• 1a. New Customer.
• 1. Perform use case Manage Membership.
• 2a. Customer ID not found.
• 1. Cashier verifies ID. If entry error,
  reenter, else Manage Membership.
• 2b. Customer has unpaid fines (usually for late
  returns).
• 1. Pay Fines.

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Use Cases example

• Special Requirements
• Language internationalization on the display
  messages and rental report.
• Large text on display. Visible from 1 m.
• Technology and Data Variations
• ID entries by bar code scanner or keyboard.
• Frequency
• Near continuous
• Open Issues
• Should we support a magnetic stripe cards for
  customer ID, and allow customer to directly use
  card reader?

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Tasks

• Choose technology and dev. environment
• Define use cases for the dito system
• At least 3 use cases (not startup/shutdown!)
• Specify supplementary specification (p104)
  performance, licensing, special features such as
  report generation
• Glossary define noteworthy terms object
  attributes, operation parameter, report layout
• Vision half page executive overview
• Sketch basic architecture (components)
• List at least 2 critical requirements
• Associate roles for the first cycle as follows
• 2 pairs of students responsible for two different
  modules