1. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 1 Supplementary Slides for Software Engineering: A Practitioner's Approach, 6/e Part 2 Supplementary Slides for Software Engineering: A Practitioner's Approach, 6/e Part 2 copyright © 1996, 2001, 2005 R.S. Pressman & Associates, Inc. For University Use Only May be reproduced ONLY for student use at the university level when used in conjunction with Software Engineering: A Practitioner's Approach. Any other reproduction or use is expressly prohibited. This presentation, slides, or hardcopy may NOT be used for short courses, industry seminars, or consulting purposes.

2. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 2 Software Engineering: A Practitioner’s Approach, 6/e Chapter 5 Practice: A Generic View Software Engineering: A Practitioner’s Approach, 6/e Chapter 5 Practice: A Generic View copyright © 1996, 2001, 2005 R.S. Pressman & Associates, Inc. For University Use Only May be reproduced ONLY for student use at the university level when used in conjunction with Software Engineering: A Practitioner's Approach. Any other reproduction or use is expressly prohibited.

3. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 3 What is “Practice”? Practice is a broad array of concepts, principles, methods, and tools that you must consider as software is planned and developed. Practice is a broad array of concepts, principles, methods, and tools that you must consider as software is planned and developed. It represents the details — the technical considerations and how to’s — that are below the surface of the software process — the things that you’ll need to actually build high-quality computer software. It represents the details — the technical considerations and how to’s — that are below the surface of the software process — the things that you’ll need to actually build high-quality computer software.

4. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 4 The Essence of Practice George Polya, in a book written in 1945 (!), describes the essence of software engineering practice … George Polya, in a book written in 1945 (!), describes the essence of software engineering practice … Understand the problem (communication and analysis). Understand the problem (communication and analysis). Plan a solution (modeling and software design). Plan a solution (modeling and software design). Carry out the plan (code generation). Carry out the plan (code generation). Examine the result for accuracy (testing and quality assurance). Examine the result for accuracy (testing and quality assurance). At its core, good practice is common-sense problem solving At its core, good practice is common-sense problem solving

5. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 5 Understand... Who are the stakeholders? Who are the stakeholders? What are the unknowns? What are the unknowns? Can the problem be compartmentalized? Can the problem be compartmentalized? Can the problem be represented graphically? Can the problem be represented graphically?

6. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 6 Plan... Have you seen similar problems before? Have you seen similar problems before? Has a similar problem been solved? Has a similar problem been solved? Can subproblems be defined? Can subproblems be defined? Can you represent the solution in a way leading to effective implementation? Can you represent the solution in a way leading to effective implementation?

7. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 7 Carry out the plan... Does the solution conform to the plan? Does the solution conform to the plan? Is each component of the solution probably correct? Is each component of the solution probably correct? Design and code reviewed? Design and code reviewed? Have correctness proofs been applied? Have correctness proofs been applied?

8. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 8 Examining the result... Is it possible to test separately each component of the solution? Is it possible to test separately each component of the solution? Does the solution produce results that conform to the data, functions, features, and behaviours required? Does the solution produce results that conform to the data, functions, features, and behaviours required?

9. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 9 Core Software Engineering Principles Provide value to the customer and the user Provide value to the customer and the user KIS—keep it simple! KIS—keep it simple! Maintain the product and project “vision” Maintain the product and project “vision” What you produce, others will consume What you produce, others will consume Be open to the future (but do not go overboard!) Be open to the future (but do not go overboard!) Plan ahead for reuse (although sometimes this might be expensive!) Plan ahead for reuse (although sometimes this might be expensive!) Think! (and learn!) Think! (and learn!)

10. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 10 Software Engineering Practices Consider the generic process framework Consider the generic process framework Communication Communication Planning Planning Modeling Modeling Construction Construction Deployment Deployment Here, we’ll identify Here, we’ll identify Underlying principles Underlying principles How to initiate the practice How to initiate the practice An abbreviated task set An abbreviated task set

11. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 11 Communication Practices Principles: Principles: Listen Listen Prepare before you communicate Prepare before you communicate Facilitate the communication Facilitate the communication Face-to-face is best Face-to-face is best Take notes and document decisions Take notes and document decisions Collaborate with the customer Collaborate with the customer Stay focused (modularize your discussion) Stay focused (modularize your discussion) Draw pictures when things are unclear Draw pictures when things are unclear Move on … (when agreed, disagreed, or unclear) Move on … (when agreed, disagreed, or unclear) Negotiation works best when both parties win. Negotiation works best when both parties win.

12. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 12 Communication Practices Initiation Initiation The parties should be physically close to one another The parties should be physically close to one another Make sure communication is interactive Make sure communication is interactive Create solid team “ecosystems” Create solid team “ecosystems” Use the right team structure Use the right team structure An abbreviated task set An abbreviated task set Identify who it is you need to speak with Identify who it is you need to speak with Define the best mechanism for communication Define the best mechanism for communication Establish overall goals and objectives and define the scope Establish overall goals and objectives and define the scope Get more detailed Get more detailed Have stakeholders define scenarios for usage Have stakeholders define scenarios for usage Extract major functions/features Extract major functions/features Review the results with all stakeholders Review the results with all stakeholders

13. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 13 Planning Practices Principles Principles Understand the project scope Understand the project scope Involve the customer (and other stakeholders): they define project priorities and constraints Involve the customer (and other stakeholders): they define project priorities and constraints Recognize that planning is iterative (not engraved in stone) Recognize that planning is iterative (not engraved in stone) Estimate (efforts, costs, duration) based on what you know Estimate (efforts, costs, duration) based on what you know Consider risk (and plan for contingencies) Consider risk (and plan for contingencies) Be realistic (people cannot be 100% efficient each day! ) Be realistic (people cannot be 100% efficient each day! ) Adjust granularity (i.e. level of detail) as you plan Adjust granularity (i.e. level of detail) as you plan Define how quality will be achieved (plan reviews, pairs, …) Define how quality will be achieved (plan reviews, pairs, …) Define how you’ll accommodate changes (timing, impact, cost) Define how you’ll accommodate changes (timing, impact, cost) Track what you’ve planned (and make adjustments) Track what you’ve planned (and make adjustments)

14. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 14 Planning Practices Identify: project objectives, milestones and schedules, responsibilities, managerial and technical approaches, required resources: Identify: project objectives, milestones and schedules, responsibilities, managerial and technical approaches, required resources: Ask Boehm’s questions [Barry Boehm, 1996]: Ask Boehm’s questions [Barry Boehm, 1996]: Why is the system begin developed? Why is the system begin developed? What will be done? What will be done? When will it be accomplished? When will it be accomplished? Who is responsible? Who is responsible? Where are they located (organizationally)? Where are they located (organizationally)? How will the job be done technically and managerially? How will the job be done technically and managerially? How much of each resource is needed? How much of each resource is needed?

15. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 15 Planning Practices An abbreviated task set An abbreviated task set Re-assess project scope Re-assess project scope Assess risks Assess risks Evaluate functions/features Evaluate functions/features Consider infrastructure functions/features Consider infrastructure functions/features Create a coarse granularity plan Create a coarse granularity plan Number of software increments Number of software increments Overall schedule Overall schedule Delivery dates for increments Delivery dates for increments Create fine granularity plan for first increment Create fine granularity plan for first increment Track progress Track progress

16. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 16 Modeling Practices We create models to gain a better understanding of the actual entity to be built We create models to gain a better understanding of the actual entity to be built Analysis models represent the customer requirements by depicting the software in three different domains: the information domain, the functional domain, and the behavioral domain. Analysis models represent the customer requirements by depicting the software in three different domains: the information domain, the functional domain, and the behavioral domain. Design models represent characteristics of the software that help practitioners to construct it effectively: the architecture, the user interface, and component-level detail. Design models represent characteristics of the software that help practitioners to construct it effectively: the architecture, the user interface, and component-level detail.

17. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 17 Analysis Modeling Practices Analysis modeling principles Analysis modeling principles Represent the information domain (flow from/to users, other systems, devices) Represent the information domain (flow from/to users, other systems, devices) Represent software functions Represent software functions Represent software behavior Represent software behavior Partition these representations (as a hierarchy) Partition these representations (as a hierarchy) Move from essence toward implementation Move from essence toward implementation Elements of the analysis model (Chapter 8) Elements of the analysis model (Chapter 8) Data model Data model Flow model Flow model Class model Class model Behavior model Behavior model

18. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 18 Design Modeling Practices Principles Principles Design must be traceable to the analysis model Design must be traceable to the analysis model Always consider architecture (interfaces, data flow, program behaviour) Always consider architecture (interfaces, data flow, program behaviour) Focus on the design of data Focus on the design of data Interfaces (both user and internal) must be designed with care Interfaces (both user and internal) must be designed with care Components should exhibit functional independence Components should exhibit functional independence Components should be loosely coupled Components should be loosely coupled Design representation should be easily understood Design representation should be easily understood The design model should be developed iteratively (to simplify it) The design model should be developed iteratively (to simplify it) Elements of the design model Elements of the design model Data design Data design Architectural design Architectural design Component design Component design Interface design Interface design

19. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 19 Construction Practices Preparation principles: Before you write one line of code, be sure you: Preparation principles: Before you write one line of code, be sure you: Understand of the problem you’re solving (see communication and modeling) Understand of the problem you’re solving (see communication and modeling) Understand basic design principles and concepts. Understand basic design principles and concepts. Pick a programming language that best meets the needs of the software to be built and the environment in which it will operate. Pick a programming language that best meets the needs of the software to be built and the environment in which it will operate. Select a programming environment that provides tools that will make your work easier. Select a programming environment that provides tools that will make your work easier. Create a set of unit tests that will be applied once the component you code is completed Create a set of unit tests that will be applied once the component you code is completed.

20. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 20 Construction Practices Coding principles: As you begin writing code, be sure you: Coding principles: As you begin writing code, be sure you: Constrain your algorithms by following structured programming [BOH00] practice. Constrain your algorithms by following structured programming [BOH00] practice. Select data structures that will meet the needs of the design. Select data structures that will meet the needs of the design. Understand the software architecture and create interfaces that are consistent with it. Understand the software architecture and create interfaces that are consistent with it. Keep conditional logic as simple as possible. Keep conditional logic as simple as possible. Create nested loops in a way that makes them easily testable. Create nested loops in a way that makes them easily testable. Select meaningful variable names and follow other local coding standards. Select meaningful variable names and follow other local coding standards. Write code that is self-documenting. Write code that is self-documenting. Create a visual layout (e.g., indentation and blank lines) that aids understanding. Create a visual layout (e.g., indentation and blank lines) that aids understanding.

21. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 21 Construction Practices Validation Principles: After you’ve completed your first coding pass, be sure you: Validation Principles: After you’ve completed your first coding pass, be sure you: Conduct a code walkthrough when appropriate. Conduct a code walkthrough when appropriate. Perform unit tests and correct errors you’ve uncovered. Perform unit tests and correct errors you’ve uncovered. Refactor the code (integrating it to the overall design architecture) Refactor the code (integrating it to the overall design architecture)

22. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 22 Construction Practices Testing Principles: Testing Principles: All tests should be traceable to requirements All tests should be traceable to requirements Tests should be planned Tests should be planned The Pareto Principle applies to testing (Roughly 80% of errors will be traceable to 20% of components - isolate suspect components for rigorous testing) The Pareto Principle applies to testing (Roughly 80% of errors will be traceable to 20% of components - isolate suspect components for rigorous testing) Testing begins “in the small” and moves toward “in the large” Testing begins “in the small” and moves toward “in the large” Exhaustive testing is not possible Exhaustive testing is not possible

23. These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 6/e and are provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001, 2005 23 Deployment Practices Principles: Principles: Manage customer expectations for each increment Manage customer expectations for each increment A complete delivery package should be assembled and tested A complete delivery package should be assembled and tested A support regime should be established A support regime should be established Instructional materials must be provided to end-users Instructional materials must be provided to end-users Buggy software should be fixed first, delivered later Buggy software should be fixed first, delivered later