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1 CS 501 Spring 2007
CS 501: Software Engineering
Lecture 26
People 1
2 CS 501 Spring 2007
Course Administration
3 CS 501 Spring 2007
From Lecture 1:Overall Aim of the Course
We assume that you are technically proficient. You know a good deal about computing, can program reasonably, can learn more on the job.
When you leave Cornell, you are going to work on production projects where success or failure costs millions of dollars.
Soon you will be in charge! It may be your money!
We want you to make your mistakes now and learn from your mistakes.
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Future Experience
What will you be doing one year from now?
Ten years from now?
1. Careers outside computing
2. Careers in which you personally continue to do technical work
3. Careers in which you are responsible for the technical work of others
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Careers outside Computing
A computing background can be valuable in any career: management, government, law, medicine, philanthropy, etc.
Education in computing is an asset:
• Computing is a vital part of almost every organization
• Education in logical thinking, tackling large tasks systematically
Education in computing is a potential weakness:
• Not every problem can be solved by rational thinking alone
• Importance of skills with people, judgment, etc.
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Technical Careers
Super-technical positions
A very few senior positions which are almost entirely technical:e.g., industrial research, universities
Even these have substantial organizational aspects
Mid-level technical positions
Numerous mid-level professional positions
Can be state-of-the-art or dead-end
Computer professional report satisfaction with their choice of careers
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Careers that take responsibility for the Technical Work of Others
A common career progression is from being a technical expert to leading others who do technical work
Senior personnel must be familiar with both the strategic organizational aspects and the computing aspects of the work, e.g.,
EntrepreneurChief Information OfficerSenior consultant
• Requires good technical insight, not detailed technical expertise
• Requires organizational, marketing, personnel, financial expertise
Product management is a good background for such positions
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Chief Information Officer
The senior person in an organization responsible for technology.
• Usually a vice president.
• Other job titles include Chief Technology Officer.
• Background is a combination of technology and management.
• May have worked as a consultant (possibly internal consultant).
Does not require detailed technical expertise.
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High Level Decision Making
Big software projects are of strategic important for organizations
• The senior management have a duty to understand the strategic decisions, the cost options, and the risks.
Senior personnel requirement: individual who is familiar with both the strategic business aspects and the computing aspects of projects.
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The Connection to the Client:CS 501 Model
Client
Software development team
Course team
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The Connection to the Client:Typical Organization
Customers
Software development
Marketing
Quality assurance
Product management
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Quality Assurance
The task of Quality Assurance is to ensure that software products are built correctly.
At Microsoft, the Quality Assurance staff is as large as the Software Development staff.
• Develop tools and methodology for creating software that is:
testablemaintainablefree of bugs
• Validate software by reviews, inspections, testing, etc.
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Product Manager
The task of the Product Manager is to ensure that the right product is built and that the right trade-offs are made between timeliness, functionality and costs.
This requires an understanding of:
• Marketing and business considerations
• Technical options and design criteria
• Communication among groups with different expertise and priorities
A good Product Manager has strong technical and management skills (e.g., a computer scientist with an MBA)
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Career Flexibility
Nobody knows where computing will go in the future, but …
If you do not learn continuously, you are going out of date fast!
• Go to seminars, conferences, training courses
• Be inquisitive – discover things for yourself
Technical expertise is most valuable when combined with other skills
• Understand the organization that you are part of, e.g., budgets, marketing.
• Develop organizational skills, e.g., presentations, writing, leadership
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Software Development as a Profession
Question: Is software development a branch of engineering?
Answer: It depends on how you define engineering.
Software development demands a high degree of
professionalism.
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What is Engineering?
A definition of engineering
The profession of:
... creating cost-effective solutions ...
... to practical problems ...
... by applying scientific knowledge ...
... and established practices ...
... building things ...
and taking responsibility for them!
With this definition, software development is clearly engineering
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From the National Society of Professional Engineers
• Only a licensed engineer may prepare, sign and seal, and submit engineering plans ... for public and private clients.
• Licensure for individuals ... is a legal requirement for those who are in responsible charge of work, ...
• Federal, state, and municipal agencies require that certain [positions] ... be filled only by licensed professional engineers.
• Many states have been increasingly requiring that those individuals teaching engineering must be licensed.
• State engineering boards are increasingly ... obtaining the authority to impose civil penalties against unlicensed individuals.
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What is Engineering?
A second definition of engineering
A professional who
… is licensed by a professional society
… based on a set educational program with a standard body of knowledge and specified experience
… who is the only person permitted to oversee certain tasks
If this is your definition of engineering it is hard to see it applied to software development
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From Lecture 1:The Craft of Software Development
Software products are very varied
--> Client requirements are very different
--> There is no standard process for software engineering
--> There is no best language, operating system, platform, database system, development environment, etc.
A skilled software developer knows about a wide variety of approaches, methods, tools. The craft of software engineering is to select appropriate methods for each project and apply them effectively.
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Crafts, Science, Engineering
Production
Craft
Commercial
Science
ProfessionalEngineering
From: Shaw and Garlan
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Crafts, Science, Engineering
Production
Craft
Commercial
Science
ProfessionalEngineering
From: Shaw and Garlan
algorithmsdata structures
compiler construction
software developmentmethodologies
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Engineers, Texas and the ACM
• Proposal in the Texas legislature to license professional engineers in Software Engineering
• What role should the ACM play?
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Software Engineering as Engineering?
• Part craft -- part engineering
• Embryonic scientific basis
• Evolving body of expertise
ACM conclusion: Software Engineering is in too much of a craft, too uncertain, and changing too much for the apparatus of a profession
• Who has the expertise to define a formal Body of Knowledge?
• What would be in an accreditation exam?
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From Lecture 1:Professional Responsibility
Organizations put trust in software developers:
• Competence: Software that does not work effectively can destroy an organization.
• Confidentiality: Software developers and systems administrators may have access to highly confidential information (e.g., trade secrets, personal data).
• Legal environment: Software exists in a complex legal environment (e.g., intellectual property, obscenity).
• Acceptable use and misuse: Computer abuse can paralyze an organization (e.g., the Internet worm).
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An Old Question: Safety Critical Software
A software system fails and several lives are lost. An inquiry discovers that the test plan did not consider the case that caused the failure. Who is responsible:
(a) The testers for not noticing the missing cases?
(b) The test planners for not writing the complete test plan?
(c) The managers for not having checked the test plan?
(d) The client for not having done a thorough acceptance test?
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Software Developers and Testers: Responsibilities
• Carrying out assigned tasks thoroughly and in a professional manner
• Being committed to the entire project -- not just tasks that have been assigned
• Resisting pressures to cut corners on vital tasks
• Alerting colleagues and management to potential problems early
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Computing Management Responsibility
• Organization culture that expects quality
• Appointment of suitably qualified people to vital tasks (e.g., testing safety-critical software)
• Establishing and overseeing the software development process
• Providing time and incentives that encourage quality work
• Working closely with the client
Accepting responsibility for work of team
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Client Responsibility
• Organization culture that expects quality
• Appointment of suitably qualified people to vital tasks (e.g., technical team that will build a critical system)
• Reviewing requirements and design carefully
• Establishing and overseeing the acceptance process
• Providing time and incentives that encourage quality work
• Working closely with the software team
Accepting responsibility for the resulting product
