CEN 5011 Advanced Software Engineering Fall 2004 Instructor: Masoud Sadjadi http://www.cs.fiu.edu/~sadjadi/Classes/CEN-5011/

Acknowledgements Dr. Peter Clarke Dr. Betty Cheng Dr. Bernd Bruegge Overview: Dr. Peter Clarke Dr. Betty Cheng Dr. Bernd Bruegge Dr. Allen Dutoit Introduction Evaluation SW Life Cycle

Agenda Course Introduction Initial Evaluation Software Life Cycle Overview: Course Introduction Initial Evaluation Software Life Cycle Introduction Evaluation SW Life Cycle

Course Home Page Web Page General Information: Important Links: Overview: Web Page http://www.cs.fiu.edu/~sadjadi/Classes/CEN-5011/ General Information: Office Hours: ECS 212C, W 14:00 - 16:00 or by appointment. Important Links: Course Syllabus Project Class Schedule, Reading Assignments, and Lecture Notes Class Notices Please read before coming to class. Pay attention to the reading assignments. Introduction Home Page SE Overview Course Outcome Evaluation SW Life Cycle

Prerequisite and References Overview: Prerequisite CEN 4010 Familiarity with At least two higher level languages The foundations of computing The basic concepts of software engineering Required Text Bernd Bruegge and Allen H Dutoit, “Object-Oriented Software Engineering: Using UML, Patterns, and Java.” Other reading material Class notes.  Introduction Home Page Syllabus Project SE Overview Course Outcome Evaluation SW Life Cycle

Grading Grading Policy Grading Standard Attendance Overview: Grading Policy Class Attendance and Participation: 10%. Homework: 20%. Term Project: 30%. Mid-Term Exam: 20%. Final Exam: 20%. Grading Standard The grading scale is: A: 90 | A-:87 | B+:84 | B: 80 | B-:77 | C+:74 | C: 70 | C-:65 | D+:60 | D: 55 | D-:50.  Note that a B- is not a B. Attendance Attendance will be taken during each class meeting. Introduction Home Page Syllabus Project SE Overview Course Outcome Evaluation SW Life Cycle

Tentative Course Schedule Overview: Week Date Deliverables/Exams Lectures 1 9/1 Introduction. Software engineering overview. 2 9/8 Homework 1 (5%) Modeling with UML. 3 9/15 Project organization. Requirements elicitation. 4 9/22 Homework 2 (5%) Requirements elicitation and analysis. 5 9/29 System design: decomposition and goals. 6 10/6 Project deliverable 1 (5%) Project presentation 1 by students. (5%) 7 10/13 Mid-term exam (20%) Object design: reuse and patterns. 8 10/20 Object design: reuse, patterns, and interfaces. 9 10/27 Homework 3 (5%) Mapping models to code. 10 11/3 Integration and system testing. 11 11/10 Project deliverable 2 (5%) Project presentation 2 by students. (5%) 12 11/17 Managing change: project management. 13 11/24 Homework 4 (5%) Transparent shaping of existing software. 14 12/1 Review the course and final exam preparation. 15 12/8 Project Deliverable 3 (5%) Project presentation 3 by students. (5%) 16 12/15 Final exam (20%) Introduction Home Page Syllabus Project SE Overview Course Outcome Evaluation SW Life Cycle

Project Objective and Grading Overview: Objective   The primary objective of this project is to give you practice in applying the phases of the software development process to a "real" software project. Grading Scheme   The grade for this project is based on three deliverables and two class presentations, representing 30% of the final grade.   All students in a project team receive the same grade. Introduction Home Page Syllabus Project SE Overview Course Outcome Evaluation SW Life Cycle

Deliverables and Presentation Overview: Introduction Deliverable 1 Software Requirements  Document (SRD) (5%) 10/6 Due at the beginning of the class. Presentation 1 A brief description of  SRD.  Details will follow. (5%) Deliverable 2 Design Document (DD) (5%) 11/10 Presentation 2 A brief description of DD.  Details will follow. (5%) Deliverable 3 Software documentation consisting of: (5%) Software Requirements  Document Design Document Implementation i.e. code design, and Test Cases User's Guide A CD with all project material. 12/8 Presentation 3 A brief description of the software system (5%) Requirements, design, implementation and test cases. The presentation should be no more than 20 mins. Home Page Syllabus Project SE Overview Course Outcome Evaluation SW Life Cycle

Project and Team Selection Overview: Selection of Project:   Each group is responsible for selecting a project.   Before starting work on the project you must come and see me during my office hours so that we can decide on the scope of your project. Project selection should be finalized by the end of Week 2 (Friday, September 10). This means you have to come and see me before September 10. If you have difficulty in selecting a project I will assist you. Project Teams   Each team shall consist of 5 to 6 students.   Let us decide on team members Introduction Home Page Syllabus Project SE Overview Course Outcome Evaluation SW Life Cycle

What is Software Engineering? (1) Overview: Systematic approach for developing software “Methods and techniques to develop and maintain quality software to solve problems.” [Pfleeger, 1990] “Study of the principles and methodologies for developing and maintaining software systems.” [Zelkowitz, 1978] “Software engineering is an engineering discipline which is concerned with all aspects of software production.” [Sommerville] Introduction Home Page SE Overview Definition How to apply? Course Outcome Evaluation SW Life Cycle

What is Software Engineering? (2) Overview: “Practical application of scientific knowledge in the design and construction of computer programs and the associated documentation required to develop, operate, and maintain them.” [Boehm, 1976] “Deals with establishment of sound engineering principles and methods in order to economically obtain software that is reliable and works on real machines.” [Bauer, 1972] Introduction Home Page SE Overview Definition How to apply? Course Outcome Evaluation SW Life Cycle

Questions Addressed by SE Overview: How do we ensure the quality of the software that we produce? How do we meet growing demand and still maintain budget control? How do we avoid disastrous time delays? Introduction Home Page SE Overview Definition How to apply? Course Outcome Evaluation SW Life Cycle

Why apply SE to Systems? Overview: Provide an understandable process for system development. Develop systems and software that are maintainable and easily changed. Develop robust software and system. Allow the process of creating computing-based systems to be repeatable and manageable. Introduction Home Page SE Overview Definition How to apply? Course Outcome Evaluation SW Life Cycle

How can we apply SE? Modeling Problem-solving Knowledge acquisition Overview: Modeling Problem-solving Knowledge acquisition Rationale-driven Introduction Home Page SE Overview Definition How to apply? Course Outcome Evaluation SW Life Cycle

Modeling Overview: “A model is an abstract representation of a system that enables us to answer questions about the system.” Why use a model? Systems are too large, too small, too complicated, or too expensive, to experience firsthand. Models allow Visualization Comprehension Introduction Home Page SE Overview Definition How to apply? Course Outcome Evaluation SW Life Cycle

Steps in problem solving: Overview: Steps in problem solving: Formulate the problem Analyze the problem Search for solutions Decide on the appropriate solution Specify the solution Introduction Home Page SE Overview Definition How to apply? Course Outcome Evaluation SW Life Cycle

Knowledge Acquisition Overview: Domain specific knowledge. New knowledge can affect the development process. Knowledge acquisition is nonlinear – affects several of the software development models. Risk assessment is important. Introduction Home Page SE Overview Definition How to apply? Course Outcome Evaluation SW Life Cycle

Rationale Management Assumptions made about systems change constantly. Overview: Assumptions made about systems change constantly. Application domain models stabilize, solution domain models are in constant flux. Changes to the solution models due to: design and implementation faults new technology Need to understand the context in which each design decision was made. Introduction Home Page SE Overview Definition How to apply? Course Outcome Evaluation SW Life Cycle

Course Outcomes Overview: Familiarity with planning and managing large scale software systems. Mastering the techniques for software requirement elicitation and analysis. Mastering the techniques for software design. Mastering the techniques for software implementation. Familiarity with techniques used to test large scale software systems. Familiarity with maintaining software and managing change. Introduction Home Page SE Overview Course Outcome Evaluation SW Life Cycle

Initial Evaluation Background Survey Initial Assessment Overview: Background Survey To get familiar with your interests in the course. To understand what topics should be covered. To get familiar with your research interests. Initial Assessment No grading value. To assess the initial level of your knowledge. To teach the course at an acceptable level. To help you fulfill the course requirements. Introduction Evaluation SW Life Cycle

Agenda Course Introduction Initial Evaluation Software Life Cycle Overview: Course Introduction Initial Evaluation Software Life Cycle Introduction Evaluation SW Life Cycle

Our Intention Requirements Software Overview: Introduction Evaluation SW Life Cycle Requirements Motivation Terminology SW Processes SW Life Cycle Cap. Maturity Software

Our plan of attack Requirements Analysis Design Implementation Testing Overview: Introduction Requirements Analysis Evaluation SW Life Cycle Design Motivation Terminology SW Processes Implementation SW Life Cycle Cap. Maturity Testing Delivery and Installation

How it often goes Requirements Analysis D E L A Y Vaporware Overview: Introduction Evaluation Requirements D E L A Y SW Life Cycle Analysis Motivation Terminology SW Processes SW Life Cycle Cap. Maturity Vaporware

Inherent Problems Requirements are complex Overview: Requirements are complex The client does not know the functional requirements in advance. Requirements may be changing Technology enablers introduce new possibilities to deal with nonfunctional requirements. Frequent changes are difficult to manage Identifying milestones and cost estimation is difficult. There is more than one software system Backward compatible with existing systems Let’s view these problems as the nonfunctional requirements for a system that supports software development! This leads us to software life cycle modeling Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity

Terminology (1) participants – all persons involved in a project. Overview: participants – all persons involved in a project. e.g., developers, project manager, client, end users. role – associated with a set of tasks assigned to a participant. system – underlying reality. model – abstraction of the reality. work product – an artifact produced during development. deliverable – work product for client. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity

Terminology (2) Overview: activity – a set of tasks performed toward a specific purpose. milestone – end-point of a software process activity. task – an atomic unit of work that can be managed and that consumes resources. goal – high-level principle used to guide the project. functional requirement – an area of functionality that the system must have. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity

Terminology (3) Overview: nonfunctional requirement – a constraint on the system. notation – is a graphical or textual set of rules representing a model (e.g., UML) method – a repeatable technique for solving a specific problem e.g. sorting algorithm methodology – a collection of methods for solving a class of problems (e.g., Unified Software Development Process). Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity

Software Processes Specification Development Validation Evolution Overview: Specification requirements elicitation and analysis. Development systems design, detailed design (OO design), implementation. Validation validating system against requirements (testing). Evolution meet changing customer needs and error correction (maintenance). Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity

Software Specification (1) Overview: Functionality of the software and constraints (non-functional requirements) on its operation must be defined. Involves: Requirements elicitation The client and developers define the purpose of the system. Output is a description of the system in terms of actors and uses cases. Actors include roles such as end users and other computers the system needs. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes Specification Development Validation Evolution SW Life Cycle Cap. Maturity

Software Specification (2) Overview: Uses cases are general sequences of events that describe all possible actions between actor and the system for a given piece of functionality. Analysis Objective: produce a model of the system that is correct, complete, consistent, unambiguous, realistic, and verifiable. Developers transform the use cases into an object model that completely describes the system. Model is checked for ambiguities and inconsistencies. Output: Object model annotated with attributes, operations, and associations. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes Specification Development Validation Evolution SW Life Cycle Cap. Maturity

Software Development (1) Overview: Producing the software that meets the specification. System Design Goals of the project are defined. System decomposed into smaller subsystems (architectural model). Strategies to build system identified HW and SW platform, data management, control flow, and security. Output: model describing subsystem decomposition and system strategies. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes Specification Development Validation Evolution SW Life Cycle Cap. Maturity

Software Development (2) Overview: Object Design Bridges the gap between analysis model and the strategies identified in the system design. Includes: Describing object and subsystem interfaces Selecting off–the-shelf components Restructure object model to attain design goals e.g., extensibility, understandability, and required performance. Output: detailed object model annotated with constraints and supporting documentation. Implementation Translation of the object model into source code. No general process followed. There are tools to assists the programmer such as CASE tools. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes Specification Development Validation Evolution SW Life Cycle Cap. Maturity

Software Development Activities Overview: Introduction Requirements Analysis Evaluation What is the problem? SW Life Cycle Motivation Terminology System Design SW Processes What is the solution? Specification Problem Domain Development Validation Implementation Domain Evolution Object Design What is the solution in a specific context? SW Life Cycle Cap. Maturity Implementation How is the solution constructed?

Software Validation (1) Overview: Ensures the software does what the customer want. The software conforms to its specification and meets the expectations of the customer. Validation: ‘Are we building the right product?’ Ensures the software meets the expectations of the customer. Verification: ‘Are we building the product right?’ Ensures the software conforms to the specification. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes Specification Development Validation Evolution SW Life Cycle Cap. Maturity

Software Validation (2) Overview: Techniques Software inspections (static): Analyze and check system representations (e.g., requirements documents, design diagrams, and program source code). Software testing (dynamic): Executing an implementation of the software with test data and examining the outputs against expected results. V&V process establishes the existence of defects. Debugging is a process that locates and corrects these defects. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes Specification Development Validation Evolution SW Life Cycle Cap. Maturity

Software Evolution Software must evolve to meet the customer needs. Overview: Software must evolve to meet the customer needs. Software maintenance is the process of changing a system after it has been delivered. Reasons for maintenance To repair faults. To adapt the software to a different operating environment. To add to or modify system’s functionality. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes Specification Development Validation Evolution SW Life Cycle Cap. Maturity

Attributes of Good Software Overview: Maintainability Ease of changing the software to meets the changing needs of the customer. Dependability Reliability, security and safety. Efficiency Responsiveness, processing time, and memory usage. Usability Appropriate user interface and adequate documentation. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes Specification Development Validation Evolution SW Life Cycle Cap. Maturity

Software Life Cycle Software life cycle modeling Software life cycle Overview: Software life cycle modeling Attempt to deal with complexity and change. Software life cycle Set of activities and their relationships to each other to support the development of a software system . Software development methodology A collection of techniques for building models, which are applied across the software lifecycle. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity

Software Life Cycle Overview: Software construction goes through a progression of states Introduction Evaluation SW Life Cycle Motivation Terminology Adulthood Childhood Retirement Conception SW Processes SW Life Cycle Cap. Maturity Pre- Development Post- Development Development

Software Life Cycle Models Overview: Waterfall model and its problems Pure Waterfall Model V-Model Iterative process models Boehm’s Spiral Model Unified Process Model Entity-based models Issue-based Development Model Concurrent Development Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Waterfall Model (1) The waterfall model Overview: The waterfall model First described by Royce in 1970 There seem to be at least as many versions as there are authorities - perhaps more Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes Requirements Definition System and software design Implementation and unit testing Integration and system testing Operation and maintenance SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Waterfall Model (2) Overview: One or more documents are produced after each phase and “signed off”. Points to note: “Water does not flow up”. it is difficult to change artifact produced in the previous phase. This model should be used only when the requirements are well understood. Reflects engineering practice. Simple management model. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

From Waterfall to V Model Overview: Horizontal lines denote the information flow between activities at the same abstraction level. Introduction Evaluation SW Life Cycle Requirements Specification System design Detailed Design Implementation Unit Test System and integration test Acceptance test Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

V Model Overview: Similar to pure waterfall model but makes explicit the dependency between development and verification activities. The left half of the V represents development and the right half system validation. Note the requirements specification includes systems reqs. analysis, reqs. elicitation, and reqs. analysis. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Spiral Model (1) Basic Idea Two types: Advantages Disadvantages Overview: Basic Idea develop initial implementation, expose it to user, and refine it until an adequate system is produced. Two types: Exploratory Throw-away prototyping Advantages model used when problem is not clearly defined. Disadvantages Process not visible, systems are poorly constructed, may require special tools and techniques. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Spiral Model (2) Design objectives, Evaluate alternatives, alternatives, and constraints Overview: Evaluate alternatives, identify and resolve risks Introduction Evaluation Risk analysis SW Life Cycle Risk analysis Motivation Terminology Risk analysis SW Processes Prototype 3 Not shown in detail SW Life Cycle Prototype 2 Prototype 1 Waterfall Requirements plan Concept of operation S/w Reqs. Detailed Design Iterative Sys. Product Design Entity-Based Development Plan Reqs. Validation Cap. Maturity Code Integration Plan Design Validation Unit Test Integration & Test Acceptance Test Develop and verify next level product Plan next phase

Spiral Model (3) Overview: Tries to accommodate infrequent change during development. Each round of the spiral involves: Determine objectives Specify constraints Generate alternatives Identify risks Resolve risks Develop and verify next level product Plan Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Incremental Development (1) Overview: Mills et al. 1980 Introduction Evaluation SW Life Cycle Motivation Terminology Define outline requirements Assign requirements to increments Design system architecture Develop system increment Validate Integrate system System incomplete Final SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Incremental Development (2) Overview: Software specification, design and implementation is broken down into a series of increments which are developed in turn. Gives customers some opportunities to delay decisions on the detailed requirements of the system. Services are identified and a priority allocated. Each increment provides a subset of the system’s functionality. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Incremental Development (3) Overview: Advantages: Customers do not have to wait for the entire system. Customers gain experience using early increments of the system. Lowers the risk of overall project failure. Most important system services receives the most testing. Disadvantages: May be difficult to map meaningful functionality into small increments. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Extreme Programming Overview: The incremental approach has evolved to ‘extreme programming’ (Beck 1988). Extreme programming: Development and delivery of very small increments. Customer involvement in the process. Constant code improvement. Egoless programming Programs are regarded as group property! Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Unified Software Development Process (1) Overview: Similar to Boehm’s spiral model. A project consists of several cycles, each ends with the delivery of a product to the customer. Each cycle consists of four phases: Inception Elaboration Construction Transition Each phase consists of a number of iterations. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Unified Software Development Process (2) Overview: Inception ends with commitment from the project sponsor to go ahead. Elaboration ends with basic architecture of the system in place, a plan for construction agreed, all significant risks identified, and major risks understood enough not to be too worried. Construction ends with a beta-release system. Transition is the process of introducing the system to it users. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Unified Software Development Process (2) Overview: System Development Introduction Evaluation Analysis model SW Life Cycle specified by Motivation Terminology realized by Design model SW Processes SW Life Cycle Use case model Waterfall distributed by Deployment model Iterative Entity-Based implemented by Cap. Maturity Implementation model Requirements captured as a set of use cases. verified by Test model

Unified Software Development Process (3) Overview: Deployment model physical communication links between hardware items. relationships between physical machines and processes. The models in the Unified Process are traceable A model element can be traced to at least one element in an associated model. Transition between models are seamless we can tell in a foreseeable way how to get from an element in one model to one/more elements in an associated model. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative Entity-Based Cap. Maturity

Issue-Based Development Overview: A system is described as a collection of issues Issues are either closed or open. Closed issues have a resolution. Closed issues can be reopened (Iteration!). The set of closed issues is the basis of the system model Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Waterfall Iterative I1:Open I2:Closed I3:Closed A.I1:Open A.I2:Open SD.I1:Closed SD.I2:Closed SD.I3:Closed Planning Requirements Analysis System Design Entity-Based Cap. Maturity

What to Choose? PT = Project Time, MTBC = Mean Time Between Change Overview: PT = Project Time, MTBC = Mean Time Between Change Change rarely occurs (MTBC >> PT): Waterfall Model All issues in one phase are closed before proceeding to the next phase Change occurs sometimes (MTBC = PT): Boehm’s Spiral Model Change occurring during a phase might lead to an iteration of a previous phase or cancellation of the project “Change is constant” (MTBC << PT) Issue-based Development (Concurrent Development Model) Phases are never finished, they all run in parallel Decision when to close an issue is up to management. The set of closed issues form the basis for the system to be developed. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity

IEEE 1074 Standard for Developing Life Cycle Processes Overview: Standard for Developing Life Cycle Processes Describes the set of activities and processes that are mandatory for the development and maintenance of software. Process is a set of activities that is performed towards a specific purpose. Processes are grouped into higher abstractions called process groups. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity

Software Processes Process Group Processes Project Management Overview: Process Group Processes Project Management Project Initiation Project Management and Control Software Quality Management Pre-development Concept Exploration System Allocation Development Requirements Design Implementation Post-development Installation Operation and Support Maintenance Retirement Integral Processes Verification and Validation Software Configuration Management Document Development Training Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity

Capability Maturity Model (CMM) Overview: 1. Initial Level ad hoc, no feedback from user, black box. 2. Repeatable Level Each project has a well-defined sw life cycle model. 3. Defined Level A document sw life cycle model for all managerial and technical activities across the org. exists. 4. Managed Level Metrics for activities and deliverables are defined. 5. Optimizing Level Process allows feedback of information to change process itself. Introduction Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity

State of the Software Industry in 1995 Overview: Introduction Maturity Level Frequency 1. Initial 70% 2. Repeatable 15% 3. Defined < 10% 4. Managed < 5% 5. Optimizing < 1% Evaluation SW Life Cycle Motivation Terminology SW Processes SW Life Cycle Cap. Maturity Source: Royce, Project Management, P. 364