Trends in Software Engineering a personal view Ivar

Trends in Software Engineering a personal view Ivar Jacobson Vice President e-Development Rational Software Corporation ivar@rational. com

Virtual Agenda w Yesterday w Tomorrow The best way to predict the future is to invent it!

The 1980 Letter to The CEO of Ericsson* * Björn Svedberg w The component-based development approach used for AKE/AXE will evolve into a world standard w Go further in three steps § 1983: present a standard method including a modeling language [like SDL, UML], a process [like RUP] supported by a first generation tool-set § 1985: the modeling language becomes a formal executable language [like UML with action semantics] § 1990: expert system support on top of process, language and tool; talked about layman programming

Component-Based Architectures w Originated 1967 -70 at Ericsson § for real-time, distributed systems: § blocks a k o components, • • design code executables run-time objects § interfaces based on signals, § functions crossed blocks -- or realized as collaborations among blocks w Components have become the standard. § No new development paradigm to replace components in sight!

Modeling Languages -- a personal w 1967 -70: The AKE/AXE modeling language: view § § block diagrams collaboration diagrams sequence diagrams state transition diagrams (state overviews, activity diagrams, concurrent states) w 1974 -82: the first object modeling standard SDL adopts those techniques § nicknamed ‘The Ericsson Language’ w In parallel Entity-Relationship modeling emerged w 1987: Objectory modeling language combined SDL and ER technologies, added Use Cases and Multi-Modeling. w 1996: The Unified Modeling Language § § based on Objectory, Booch and OMT from 1991 plus many other modeling ideas The standard modeling language UML 2. 0 a major new release, followed by more. . .

Development Process -- a personal view w 1967 -70 The AKE/AXE method § functional spec’s § software architecture description § functional descr’s, block descriptions, separate from interface (signal) descriptions § functional tests and system test w 1987 -95 The Objectory Process § engineered process to facilitate specializations and instantiations (projects) § use cases drive the business track, the system track and the user track w 1996 -2000: The Rational Unified Process § § iterative development architecture-centric tool support for process engineering and process instantiations de-facto standard for e-development

Future of Software w We have the standard modeling language w We have a standard development process w What next? § § A Software Component Marketplace Quality from the Beginning Give Soul to Software Process A Complete UML Based Software Platform

A Software Component Marketplace w. A component industry including § Component factories provide ‘components’ § System Integrators reuse these ‘components’ § ‘Components’ are component systems used to build families of application systems w. We need a standard for playing on this marketplace § How to design for reuse § How to design with reuse We have a standard language, we have a standard process and there are tools. Now’s the time!

Reuseable Assets w Reuse of all models, that is of everything § architecture -- most important but just a fraction of what is reusable § use cases, analysis, design, implementation and test § user interface models, business models, etc. w Reuse of technology § process with tools § projects § guidelines

The Reuse Initiative: e-Development Accelerator Reusable Frameworks Technology or domain specifi reusable assets with associate associat guidelines on usage. Reuse Standards Open UML-based standard expressing how to document and produce reusable assets. Automation Tool support for creating, managing, and reusing software assets.

Layered System Architecture Examples of reusable object Application-specific layer Application-general layer Middleware layer System-software layer Application System Component System Component System Application System Component System Car Sales Management Customer profile Order management Shopping cart Credit card authorization Object persistency mechanism

Quality from the Beginning We have lost two generations of developers who think they just need to debug at the end, when the instead shouldn’t introduce any defects along the way. w. An attitude problem § “bugs are nice, defects are bad” § “some developers make the dirt, others (customers) clean up” w. Process change § verify and test along the way -- activity-based verification § there is no test model, test artifacts are part of all models

Activity-Based Verification Whatever you do, you are not done until you have verified that you did what you wanted to do. w. Introduce verification on activities § Each activity-artifact pair needs a Verification Case § Each Verification Case has a corresponding Verification Step § Test Cases are specializations of Verification Cases, related to the executable system

Software Process Comes Alive Development steps w The process at your fingertips w The process gets soul § the third step 20 years ago § a software engineering breakthrough technology

The Process at Your Fingertips Rational Unified Process (RUP) Is specialized to My Unified Process Is enacted as My Project And to My tasks

Process gets soul: people may be humans Traditional processes hold static rules and regulations, but lacks “soul” and adaptive capabilities. They appeal to structured reasoning, but not to the creative (lateral) spirit. Static Structured Re-Invent Generic Long-Term Learn Dynamic Creative Reuse Streamlined and Personalized Short-Term Do

Agents Software Components, but… w Autonomous w Pro-Active w Encapsulate Knowledge as Rules w Adaptive Agent (in software)

Each Developer has its Own Personal Agent System Personal Agent (for Joe) Joe (Developer) Individuals play roles in software development www. jaczone. com

Every Role in RUP is Matched to One Agent System Role Agent (for System Analyst) System Analyst www. jaczone. com

Personal Agents and Role Agents Agent System Role Agent (for System Analyst) Personal Agent (for Joe) Joe (Developer) Role Agent (for Business-Process Analyst) Since a developer can play many roles his/her personal agent may collaborate with several role agents

Specialist Agents w Rule agents § Reuse agents suggest candidate patterns, frameworks, etc § Workflow agents suggest micro-activities based on state § Conversation agents for conversational modeling § Model completion agents § Round-trip modeling agents between all kinds of models § Evaluation agents w Broker agents www. jaczone. com

A Complete UML Based Platform w An executable UML § a programming language (or a set of PL’s) § Java, C++ become superfluous § combines graphical and program-like syntax w Semantics of changes -- functional and structural -- defined by UML § language defined configuration and version management w Removing seams (or gaps) between UML and § operating systems and database mgmt systems § computer architectures "Function Distribution in Computer System Architectures”, Harold “Bud” Lawson, 1976

Every Layer of Components described in UML w Systemware components § operating systems § database management systems w Middleware components § Customer relationship management § Content management § Change management w Application general components § Subscriber management § Digit analysis node § Route data

Trend: Focus moves upwards Req. ts Analysis Design Impl. Test More “generation”=work elimination Now Tomorrow w Use cases generate test cases and input to analysis w Analysis will generate implementation;

Summary We have UML, RUP and tools w Eventually we will get a Component Industry w We will do things right from the beginning w Process will get soul -- developers are people and people are humans w We will get rid of seams and gaps between levels Tomorrow, Life will be Much Better!

Readings by Ivar Jacobson w Unified Software Development Process Jacobson, Booch, Rumbaugh, Addison Wesley Longman (1999) w Object-Oriented Software Development--A Use Case Driven Approach (Addison Wesley) Ivar Jacobson, Addison Wesley Longman (1992) w The Object Advantage: Business Process Reengineering with Objects (Addison Wesley) Ivar Jacobson, Addison Wesley Longman (1994) w Software Reuse: Architecture, Process and Organization for Business Success (Addison Wesley) Ivar Jacobson, Addison Wesley Longman (1997) w The Road to the Unified Software Development Process

Special readings w Software Reuse: Architecture, Process and Organization for Business Success (Addison Wesley) Ivar Jacobson, Addison Wesley Longman (1997) w Function Distribution in Computer System Architectures, Harold “Bud” Lawson (1976)