CPSC 4175 Intro to Software Engineering

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CPSC 4175Intro to Software Engineering

• Fall 2006
• Neal L. Rogers, PhD

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What is engineering?
How can we engineer software?
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Course description

• Catalog
• CPSC4175 Intro to Software Engineering
• Credits 3 (3 hours lecture)
• Official Description Process models of the
  software life cycle as well as methods and tools
  for software development.
• Prerequisite CPSC2108 (C or better), Senior
  Standing
• Strategic Objectives
• To provide a view of process-oriented software
  engineering
• To provide exposure to common engineering
  processes
• To provide an insight into personal software
  skills

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Syllabus

• Software engineering raison dêtre (1)
• Process foundations (1)
• Common process elements (3)
• Conceptual design (4)
• Size estimation (4)
• Task decomposition (1)
• Scheduling (4)
• Measurements (2)
• Reviews (2)
• Technical templates (4)
• Scaling up (4)
• Misc processes (4)
• Process descriptions (4)
• Infrastructure (2)
• Retrospective (1)

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Course objectives

• understand the purpose and reason for processes
• know the processes identified as being necessary
  for successful software production
• understand the what a life cycle is, its
  component parts, and how it affects the software
  production process
• understand the planning process
• understand how to define size, measure it, and
  estimate it
• understand how to decompose work units
• understand task dependencies, be able to
  construct and analyze a dependency chart
• be able to estimate software cost understand the
  process of risk management
• understand the purpose and function of status
  reviews
• understand process/product measurement, be able
  to measure and analyze a sample project
• understand own personal performance

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Who?

• Instructor Neal L. Rogers, PhD
• Office TECH 425
• Voice [phone]
• E-mail Rogers_Neal_at_colstate.edu
• WWW http//csc.colstate.edu/rogersOffice
  Hours MW 430 700, TR 300 700
• Drop-ins OK, but subject to preemption
• Course Site http//cougarnet.colstate.edu

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What?

• Course materials
• Course notes
• Class slides (.ppt format)
• available via course site
• slides will be posted by 1000 AM the day of
  class
• Other
• Excel-compatible spreadsheets
• Programming languages (Java, C/C, C, COBOL,
  etc.)
• Humphrey, Watts S. 2005. PSP A
  Self-Improvement Process for Software Engineers.
  Addison Wesley, ISBN 0-321-30549-3
• Humphrey, Watts S. 1995, A Discipline for
  Software Engineering, Addison Wesley, ISBN
  0-201-54610-8

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Expectations

• Grading
• Instructor Evaluation (On Time, Etc.) 10
• Quizzes (pop and announced) 10
• Out-of-class assignments (Programs) 80
• Submitting work
• MUST be your own work!
• Programs must be working.
• Submit assignments on time. 10 penalty per day
  late
• Attendance
• Be here!
• You are responsible for obtaining missed lectures

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Expectations

• Assignment forecast

Subject Area Mastery Demonstrated by
Due Baseline process Rudimentary statistics
program Week 2 Estimation Size counting
program Week 4 Defect analysis Proxy counting
program Week 6 Estimation LOC Added Week
8 Scheduling LOC Deleted Week 10 Design Measurem
ent LOC Modified Week 14 Process postmortem Your
metrics in Spreadsheet! Week 16
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Expectations

• Rules of Engagement
• The basic pedagogical precept ... is that all
  genuine learning arises from the activity of the
  learner's own mind. It may be assisted, guided,
  and stimulated by the activity of teachers. But
  no activity on the part of teachers can ever be a
  substitute and become the sole cause of a
  student's learning. When the activities
  performed by the teachers render students
  passive, the latter cease to be learners --
  memorizers, perhaps, but not learners.
  Mortimer Adler

• Your Responsibilities
• Be present (mentally and physically) and on
  time
• Be receptive to new ideas
• Interact
• Get involved
• Get excited

• My Responsibilities
• Be present (mentally and physically) and
  prepared
• Guide
• Facilitate
• Assess
• Excite

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What is engineering?
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Engineering

• is the profession in which knowledge of the
  mathematical and natural sciences gained by
  study, experience, and practice, is applied with
  judgment to develop ways to use, economically,
  the materials and forces of nature for the
  benefit of mankind. - ABET (formerly,
  Accreditation Board for Engineering and
  Technology)
• entails responsibilities
• knowing things
• developing judgment
• applying knowledge via judgment realistically
• acting responsibly

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What is software engineering?

• Attendant questions
• Can software be engineered?
• How can we engineer software?
• Is software engineering a legitimate engineering
  field?
• Do software engineers really live on Twinkies and
  Ding-Dongs?

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Challenges

• B. Reid on building software
• the first engineering discipline in which the
  complexity of the objects created is limited
  solely by the skill of the creator, not by the
  strength of the raw material.
• F. Brooks on inherent properties of software
  systems
• complexity Many of the classic problems of
  developing software products derive from ...
  essential complexity and its nonlinear increases
  with size. From the complexity comes the
  difficulty of communications ... of understanding
  ...
• conformity The software engineer must master
  arbitrary complexity, forced without rhyme or
  reason.
• changeability Software is pure thought-stuff,
  infinitely malleable.
• invisibility Software remains inherently
  unvisualizable.

Brooks, F. P., Jr. 1987. No Silver Bullet.
Computer 20, 4, 10-19.
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What makes a project successful?

• User Perspective
• project team understood needs
• vital changes accommodated
• progress reported
• product timely
• product useful

• Executive Perspective
• not oversold or overcommitted
• milestones achieved
• costs controlled
• customer enthusiastic

• Project Team Perspective
• involved in planning and execution
• policies well communicated
• adequate tools provided
• humane treatment by management and user

• Project Leadership Perspective
• determined user needs
• resources available
• schedules realistic
• change controlled
• progress tracked
• management supportive

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Classic Mistakes

• People-related Process-related Product-related Tec
  hnology-related
• Undermined Overly optimistic Requirements
  Silver-bulletmotivation schedule gold-plating
  syndrome
• Weak personnel Insufficient
  risk Feature Overestimation of
• Uncontrolled management creep savings from
  toolsproblem people Contractor
  failure Developer Switching tools
• Heroics Insufficient planning gold-plating
  midstream
• Adding people Abandonment Push-me, Lack
  of automatedto late project of planning in
  crisis pull-me source control
• Poor work Wasted time during negotiationenv
  ironment fuzzy front end
• etc etc etc etc

How can we minimize these mistakes?
McConnell, S. 1996. Rapid Development.
Microsoft Press
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Our goal this semester

• ... is to examine the aspects of software
  production that will give the greatest
  probability of success
• develop engineering heuristics
• identify processes unique to software production
  (production maintenance or development)

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Software engineering is ???
Using software
Understanding computers
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Software engineering is ???
Writing programs
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Software engineering is ???
design
CASE
coding
maintenance
architecture
structured analysis
KLOC
software quality assurance
control structure diagrams
testing
project management
dataflow diagrams
requirements
object-oriented technology
metrics
configuration management
structure charts
verification and validation
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Software engineering is ???
the discipline of producing software Schach
the set of tasks that comprise development,
operation, and maintenance of software
IEEE
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Software engineering is

• ... the business of developing working solutions
  through software. Umphress

Our Vision
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Software Engineering Perspective

• Laws of physics
• time lags, weight
• Laws of software
• sorting, halting, NP,
• Challenge of algorithms
• compression, knowledge representation,
• Difficulty of distribution
• Deutsch fallacies
• Problems of design
• rise in levels of abstraction, discovery of
  patterns
• Importance of organization
• team organization, multiple stakeholders
• Impact of economics
• PerformanceComplexityProcess ? Teams ? Tools
• Influence of politics
• mgmt-worker misalignment, software-as-pawn
• Limits of imagination

traditional of CS
traditional of SwE
G. Booch. Keynote. Software Technology
Conference 2002.
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Software Engineering Perspective

• Software development is fundamentally hard
• Software dis-economy cost doesnt decrease with
  volume, but increases
• Our task to create illusion of simplicity, but
  in so doing, we trade simplicity at one level of
  abstraction for complexity at another

cost/schedule
performance
function
compatibility
capacity
scalability
reliability
interoperability
technology churn
security
etc
G. Booch. Keynote. Software Technology
Conference 2002.
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But

• no matter how you slice it
• Mathematical principles involved
• Engineering discipline employed
• Managerial and technical facets orchestrated via
  defined processes to sustain a viable solution

Identify
Synthesize
Articulate
Interpret
Technical
TOOLS
People
Organize
Staff
Direct
Plan
Control
Process
Product
Property
Success
Lifecycle
Infra
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Technical facets

• ... activities that require special knowledge and
  skills in working with computers
• Identify
• determine what the problem space is
• Synthesize
• map the problem into a solution space
• Articulate
• communicate the solution space
• Interpret
• validate/verify the product of the solution
  process

Technical
Identify
Synthesize
Articulate
Interpret
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People facets

• ... activities that require special skills for
  directing the wetware
• Plan
• determine actions needed to produce product
• Organize
• determine who does what when
• Staff
• determine who
• Direct
• motivate and lead
• Control
• direct effort, measure outcome

People
Organize
Staff
Direct
Plan
Control
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Process facets

• ... the system of all enterprise tasks involved
  in production and evolution of a software product
  through the life cycle
• Life cycle model
• sequence of technical tasks required to produce a
  product (e.g., analysis, design, testing, etc.)
• Product model
• tasks needed to produce an artifact in a specific
  form
• Property model
• tasks needed to attain desired cost, schedule,
  security, reuse
• Success model
• tasks needed to assure and assess correctness
• Infrastructure model
• support mechanisms needed to engineer a solution

Process
Product
Property
Success
Lifecycle
Infra
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Summary
Topics
Key Points

• Course overview
• Software engineering raison detre
• Software engineering defined

• Software engineering is the business of
  developing solutions through software
• Producing software solutions is difficult
• Difficult activities require structure
• Engineering discipline enforces structure