Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 1 Informatics 43 Introduction to Software Engineering Lecture 8-1 November 17, 2015 Emily Navarro Duplication of course material for any commercial purpose without the explicit written permission of the professor is prohibited.

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 2 Today’s lecture Reminders Software Process Models – Build-and-fix – Waterfall – Rapid Prototyping – Incremental Homework 3

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 3 Today’s lecture Reminders Software Process Models – Build-and-fix – Waterfall – Rapid Prototyping – Incremental Homework 3

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 4 Reminder: Essential Ingredients of Software Engineering People – who else would do the work? – range from novice to very experienced Processes – to organize and manage the efforts of individuals – range from informal to very formal Tools – to support the people and the processes – range from simple to very advanced

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 5 Reminder: Processes Essential to achieve a quality product Scarce resource – quality – suitability – cost Many different kinds of processes – bug tracking – change approval – quality assurance – software life cycle

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 6 More Reminders Essential qualities – Complexity – Conformity – Changeability – Intangibility Potentially drastic or disastrous consequences Software engineering is hard, and we need processes to help!

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 7 Today’s lecture Reminders Software Process Models – Build-and-fix – Waterfall – Rapid Prototyping – Incremental Homework 3

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 8 Processes as a Remedy Software is engineered via a defined process – Cover all steps from initial idea and requirements to delivery, maintenance, and final retirement – Make sure we do the right things/we do things right – Make sure we do not forget to do anything – Different processes for different kinds of software Not a silver bullet [Brooks “No Silver Bullet”] – Software is still intrinsically difficult to deal with – Processes help, but cannot guarantee anything Remember: People + Processes + Tools  Product

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 9 Processes Elements – Activities (“Phases”) – Artifacts Requirements document, design document, code, test cases… – Resources People (their time and their cost) Tools (their time and their cost) Relationships between the elements – Precedence, requires, provides, refines to, … Constraints – Time – Cost – Qualities (repeatable process?)

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 10 Fun with Models Fashion Student

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 11 Fun with Models Fashion Student Model = Ideal

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 12 Fun with Models Software Process Model Waterfall Prototype Spiral Architecture Model Layered Client Server Model View Controller Model = Simplified Representation

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 13 Fun with Models public class Elephant { int weight; // in kg String name; Species species; public void forage() {.... } Model = Simplified Representation

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 14 What is Software Process Model for? “Prescriptive” – enforcing rules “Descriptive” – serving to describe or characterize

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 15 Software Life Cycle Models Build-and-fix Waterfall Rapid prototyping Incremental Spiral Rational Unified Process (RUP) Open Source Software (OSS) Extreme Programming (XP) Agile A software life cycle model is a high-level process

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 16 Today’s Lecture Reminders Software Process Models – Build-and-fix – Waterfall – Rapid Prototyping – Incremental Homework 3

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 17 Build-and-Fix Build first version Modify until client is satisfied Operations mode Retirement Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 18 Build-and-Fix Build first version Modify until client is satisfied Operations mode Retirement Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 19 Build-and-Fix Build first version Modify until client is satisfied Operations mode Retirement Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 20 Build-and-Fix Build first version Modify until client is satisfied Operations mode Retirement Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 21 Build-and-Fix Build first version Modify until client is satisfied Operations mode Retirement Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 22 Build-and-Fix Build first version Modify until client is satisfied Operations mode Retirement Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 23 So… What is it good for? (strengths) What is it bad for? (weaknesses)

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 24 So… What is it good for? (strengths) – Small programs that do not require much maintenance What is it bad for? (weaknesses)

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 25 So… What is it good for? (strengths) – Small programs that do not require much maintenance What is it bad for? (weaknesses) – Any nontrivial project

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 26 Today’s Lecture Reminders Software Process Models – Build-and-fix – Waterfall – Rapid Prototyping – Incremental Homework 3

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 27 Waterfall First documented by Royce in 1970 (!) Has withstood the test of time – Still being used worldwide… – But not without problems…

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 28 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 29 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 30 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 31 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 32 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 33 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 34 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 35 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 36 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 37 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 38 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 39 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 40 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 41 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 42 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 43 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 44 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 45 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 46 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 47 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 48 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 49 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 50 Waterfall Operations mode Retirement Requirements phase Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 51 SimSE Waterfall Demo

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 52 So… What is it good for? (strengths) What is it bad for? (weaknesses)

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 53 So… What is it good for? (strengths) – Promotes understanding of requirements first – Disciplined, rigorous, formal Each step ends with testing/QA – Lots of documentation – Easy to track progress – Provides a framework upon which to create more dynamic, realistic processes – Good for short, simple projects will well-understood requirements What is it bad for? (weaknesses)

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 54 So… What is it good for? (strengths) – Promotes understanding of requirements first – Disciplined, rigorous, formal Each step ends with testing/QA – Lots of documentation – Easy to track progress – Provides a framework upon which to create more dynamic, realistic processes – Good for short, simple projects will well-understood requirements What is it bad for? (weaknesses) – No iterations – Limited user input – Bad for long-term projects with any ambiguity in requirements –

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 55 Today’s Lecture Reminders Software Process Models – Build-and-fix – Waterfall – Rapid Prototyping – Incremental Homework 3

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 56 Rapid Prototyping Operations mode Retirement Build and discard simple prototype Verify Specification phase Verify Design phase Verify Implementation phase Test Integration phase Test Changed requirements Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 57 Today’s Lecture Reminders Software Process Models – Build-and-fix – Waterfall – Rapid Prototyping – Incremental Homework 3

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 58 FOR EACH BUILD Perform detailed design, implementation, and integration. Test. Deliver to client. Incremental Operations mode Retirement Requirements phase Verify Specification phase Verify Architectural design Verify Development Maintenance

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 59 Case Study: MS evolves their software process Before (Windows 8 and earlier) – “Ta-da” approach – First release 2/3 of the way through development After (Windows 10) – Iterative First release 1/3 of the way through development – Prototypes – User feedback Too much? – A/B testing

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 60 Today’s Lecture Reminders Software Process Models – Build-and-fix – Waterfall – Rapid Prototyping – Incremental Homework 3

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 61 Homework 3 Multi-person – What if people “step on each other’s toes?” – What if people need to access each other’s files? Multi-version – Each version has some shared files, and some files specific to that version – Versions may replace each other over time – A prior version may need to be examined or modified

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 62 Version Control Software a.k.a. “Revision control,” “Source control” Manages changes over time by multiple people

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 63 Homework 3 Homework 3 will introduce you to the concepts and software behind version control, using the example of Git Three parts – Part A (due 11/24) Install Git Perform some basic commands – Part B (due 12/1) Create a local repository – Part C (due 12/3) Download and examine a public repository

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 64 Homework 3 Homework 3 is posted For technical help/questions with the assignment, post on Piazza (try Google first for general issues) Attend discussion tomorrow for an introduction to Git

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 65 Reminder Homework 2 due tomorrow, Wednesday 11/18, 11:55pm – No late assignments accepted except for extenuating circumstances as described in first lecture

Department of Informatics, UC Irvine SDCL Collaboration Laboratory Software Design and sdcl.ics.uci.edu 66 Next time More software process models