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The Essence Initiative
The Essence Initiative Ivar Jacobson Agenda Specific Problems A Case for Action - Defining a solid theoretical base - Finding a kernel of widely agreed elements Using the Kernel Final Words Being in the software development business Everyone of us knows how to develop our software, but as a community we have no widely accepted common ground A CASE FOR ACTION STATEMENT • Software engineering is gravely hampered today by immature practices. Specific problems include: – The prevalence of fads more typical of fashion industry than of an engineering discipline. – The lack of a sound, widely accepted theoretical basis. – The huge number of methods and method variants, with differences little understood and artificially magnified. – The lack of credible experimental evaluation and validation. – The split between industry practice and academic research. Agenda Specific Problems A Case for Action - Defining a solid theoretical base - Finding a kernel of widely agreed elements Using the Kernel Final Words The SEMAT initiative Software Engineering Method and Theory www.semat.org Founded by the Troika in September 2009: Ivar Jacobson – Bertrand Meyer – Richard Soley What are we going to do about it? The Grand Vision We support a process to refound software engineering based on a solid theory, proven principles and best practices The Next Steps Defining A Kernel of a solid widely agreed theoretical basis elements There are probably more than 100,000 methods Desired solution: Method Architectureincl. for instance SADT, Booch, OMT, RUP, CMMI, XP, Scrum, Lean, Kanban There are around 250 The Kernel includes identified practices incl such elements as for instance use cases, Requirement, use stories, features, Software system, components, Work, Team, Way-of- working, etc. -
Formal Specification Methods What Are Formal Methods? Objectives Of
ICS 221 Winter 2001 Formal Specification Methods What Are Formal Methods? ! Use of formal notations … Formal Specification Methods ! first-order logic, state machines, etc. ! … in software system descriptions … ! system models, constraints, specifications, designs, etc. David S. Rosenblum ! … for a broad range of effects … ICS 221 ! correctness, reliability, safety, security, etc. Winter 2001 ! … and varying levels of use ! guidance, documentation, rigor, mechanisms Formal method = specification language + formal reasoning Objectives of Formal Methods Why Use Formal Methods? ! Verification ! Formal methods have the potential to ! “Are we building the system right?” improve both software quality and development productivity ! Formal consistency between specificand (the thing being specified) and specification ! Circumvent problems in traditional practices ! Promote insight and understanding ! Validation ! Enhance early error detection ! “Are we building the right system?” ! Develop safe, reliable, secure software-intensive ! Testing for satisfaction of ultimate customer intent systems ! Documentation ! Facilitate verifiability of implementation ! Enable powerful analyses ! Communication among stakeholders ! simulation, animation, proof, execution, transformation ! Gain competitive advantage Why Choose Not to Use Desirable Properties of Formal Formal Methods? Specifications ! Emerging technology with unclear payoff ! Unambiguous ! Lack of experience and evidence of success ! Exactly one specificand (set) satisfies it ! Lack of automated -
Design by Contract: the Lessons of Ariane
. Editor: Bertrand Meyer, EiffelSoft, 270 Storke Rd., Ste. 7, Goleta, CA 93117; voice (805) 685-6869; [email protected] several hours (at least in earlier versions of Ariane), it was better to let the computa- tion proceed than to stop it and then have Design by to restart it if liftoff was delayed. So the SRI computation continues for 50 seconds after the start of flight mode—well into the flight period. After takeoff, of course, this com- Contract: putation is useless. In the Ariane 5 flight, Object Technology however, it caused an exception, which was not caught and—boom. The exception was due to a floating- point error during a conversion from a 64- The Lessons bit floating-point value, representing the flight’s “horizontal bias,” to a 16-bit signed integer: In other words, the value that was converted was greater than what of Ariane can be represented as a 16-bit signed inte- ger. There was no explicit exception han- dler to catch the exception, so it followed the usual fate of uncaught exceptions and crashed the entire software, hence the onboard computers, hence the mission. This is the kind of trivial error that we Jean-Marc Jézéquel, IRISA/CNRS are all familiar with (raise your hand if you Bertrand Meyer, EiffelSoft have never done anything of this sort), although fortunately the consequences are usually less expensive. How in the world everal contributions to this made up of respected experts from major department have emphasized the European countries, which produced a How in the world could importance of design by contract report in hardly more than a month. -
Daten Als Objekte Speichern Mit Db4o, Eine Objektorientierte Datenbank
Daten als Objekte speichern mit db4o, eine objektorientierte Datenbank Matthias Bordach Universitaet Siegen [email protected] ABSTRACT 2. DER ODMG STANDARD[1] Die Hausarbeit befasst sich mit der Datenbanktechnologie Verschiedene Ans¨atze fur¨ eine Datenbank auf objektorientier- db4o. Das objektorientierte Speicherkonzept zeichnet sie als ter Basis erforderten einen Standard. Diesen Standard ent- einen Vertreter der NO-SQL-Familie aus. Auf eine theoreti- wickelte eine Arbeitsgruppe der Object Management Group sche Einfuhrung¨ in den Standard ODMG folgt eine praktische (OMG). 1993 wurde die erste Version ver¨offentlicht mit dem Vorstellung der Datenbankfunktionalit¨at. Die Funktionen Namen The Object Data Standard ODMG. Die Arbeitsgrup- werden mit Beispielen gestutzt,¨ die in Java geschrieben sind. pe uberarbeitete¨ und erweiterte das Dokument in den fol- Abfrage- und Speichermethoden werden ebenso erkl¨art wie genden Jahren. Inhalt und Ziel des Dokuments ist eine Stan- die Realisierung von Beziehungen zwischen Objekten und darddefinition von Konzepten fur¨ die Anbindung eines objek- das Handling von Schema Evolution. Der Leser wird nach torientierten Datenbankmanagementsystems an die gew¨ahlte der Lekture¨ in der Lage sein, eine einfache Datenbank mit Programmiersprache. In Version 3 wird den Sprachen C++, db4o zu programmieren. Smalltalk und Java jeweils ein eigenes Kapitel fur¨ die Schnitt- stellenumsetzung gewidmet. Generell definiert die ODMG das Object Model, Objektspezifikationssprachen und die an die 1. EINLEITUNG SQL angelehnte Object Query Language (OQL). Es werden Die Idee einer Datenbank, die Objekte ohne ein aufwendiges Standardausdrucke¨ festgelegt fur¨ die Datenbankinstanziie- Mapping in ein anderes Datenmodell speichern kann, wurde rung, -nutzung (open, close), Transaktionen (commit) und erstmals in den 80er Jahren des letzten Jahrhunderts in kon- Mehrfachzugriff (Locks). -
Making Sense of Agile Methods Bertrand Meyer Politecnico Di
Making sense of agile methods Bertrand Meyer Politecnico di Milano and Innopolis University Some ten years ago, I realized that I had been missing something big in software engineering. I had heard about Extreme Programming early thanks to a talk by Pete McBreen at a summer school in 1999 and another by Kent Beck himself at TOOLS USA in 2000. But I had not paid much attention to Scrum and, when I took a look, noticed two striking discrepancies in the state of agile methods. The first discrepancy was between university software engineering courses, which back then (things have changed) often did not cover agility, and the buzz in industry, which was only about agility. As I started going through the agile literature, the second discrepancy emerged: an amazing combination of the best and the worst ideas, plus much in-between. In many cases, faced with a new methodological approach, one can quickly deploy what in avionics is called Identification Friend or Foe: will it help or hurt? With agile, IFF fails. It did not help that the tone of most published discussions on agile methods (with a few exceptions, notably [1]) was adulatory. Sharing your passion for a novel approach is commendable, but not a reason to throw away your analytical skills. A precedent comes to mind: people including me who championed object-oriented programming a decade or so earlier may at times have let their enthusiasm show, but we did not fail to discuss cons along with pros. The natural reaction was to apply a rule that often helps: when curious, teach a class; when bewildered, write a book. -
Relational and Object-Oriented Databases
Relational and Object-Oriented Databases by Willi-Hans Steeb International School for Scientific Computing Contents 1 What is a table? 1 1.1 Introduction . 1 1.2 Examples . 5 1.3 Tables in Programs . 8 1.4 Table and Relation . 33 2 Structured Query Language 35 2.1 Introduction . 35 2.2 Integrity Rules . 38 2.3 SQL Commands . 39 2.3.1 Introduction . 39 2.3.2 Aggregate Function . 40 2.3.3 Arithmetic Operators . 40 2.3.4 Logical Operators . 40 2.3.5 SELECT Statement . 41 2.3.6 INSERT Command . 45 2.3.7 DELETE Command . 46 2.3.8 UPDATE Command . 47 2.3.9 CREATE TABLE Command . 48 2.3.10 DROP TABLE Command . 51 2.3.11 ALTER TABLE Command . 52 2.4 Set Operators . 53 2.5 Views . 60 2.6 Primary and Foreign Keys . 62 2.7 Datatypes in SQL . 63 2.8 Joins . 66 2.9 Stored Procedure . 71 2.10 MySQL Commands . 72 2.11 Cursors . 73 2.12 PL and SQL . 75 2.13 ABAP/4 and SQL . 76 2.14 Query Processing and Optimization . 77 i 3 Normal Forms 83 3.1 Introduction . 83 3.2 Anomalies . 87 3.3 Example . 89 3.4 Fourth and Fifth Normal Forms . 93 4 Transaction 101 4.1 Introduction . 101 4.2 Data Replication . 107 4.3 Locks . 108 4.4 Deadlocking . 111 4.5 Threads . 117 4.5.1 Introduction . 117 4.5.2 Thread Class . 119 4.5.3 Example . 121 4.5.4 Priorities . 123 4.5.5 Synchronization and Locks . -
Object-Oriented Software Construction
Quotes from∗ Object-Oriented Software Construction Bertrand Meyer Prentice-Hall, 1988 Preface, p. xiv We study the object-oriented approach as a set of principles, methods and tools which can be instrumental in building \production" software of higher quality than is the norm today. Object-oriented design is, in its simplest form, based on a seemingly elementary idea. Computing systems perform certain actions on certain objects; to obtain flexible and reusable systems, it is better to base the structure of software on the objects than on the actions. Once you have said this, you have not really provided a definition, but rather posed a set of problems: What precisely is an object? How do you find and describe the objects? How should programs manipulate objects? What are the possible relations between objects? How does one explore the commonalities that may exist between various kinds of objects? How do these ideas relate to classical software engineering concerns such as correct- ness, ease of use, efficiency? Answers to these issues rely on an impressive array of techniques for efficiently producing reusable, extendible and reliable software: inheritance, both in its linear (single) and multiple forms; dynamic binding and poly- morphism; a new view of types and type checking; genericity; information hiding; use of assertions; programming by contract; safe exception handling. Efficient implementation techniques have been developed to allow practical application of these ideas. [T]he book relies on the object-oriented language Eiffel. 4.1 Process and Data (p. 41) A software system is a set of mechanisms for performing certain actions on certain data. -
Title of Presentation
Essence Kernel Kristian Sandahl Essence/Kristian Sandahl 2021-01-18 2 Software Engineering Method And Theory • A common ground for software engineering • Moving away from SE methods “fashion” industry. • Founded in 2009 by: – Ivar Jacobson – Bertrand Meyer – Richard Soley • OMG Standard under the name Essence • The SEMAT Kernel – manifestation of the common ground Essence/Kristian Sandahl 2021-01-18 3 The Kernel • comprises the central elements for all SE methods; • provides a common language for comparing, applying, and improving methods; • supports progress monitoring; • works in small- and large-scale projects; • works for well documented and less documented projects; • comes with a language and tool for developing practices. • Uptake in China, Russia, South Africa, Japan, Silicon Valley, Florida, Mexico, Germany Essence/Kristian Sandahl 2021-01-18 4 What’s in it for us? • It is highly probable that this will be used much more in the future. • By focusing on the Essentials, the project groups have more freedom and responsibility. • Our students will not become “methodists”. • Taught in TDDE46 Software quality. Essence/Kristian Sandahl 2021-01-18 5 Areas of concern Use and exploitation of the system Specification and development The team and approach of work Essence/Kristian Sandahl 2021-01-18 6 What is an ALPHA? • Alpha is an acronym for an Abstract-Level Progress Health Attribute. • A critical indicator of things that are most important to monitor and progress. Essence/Kristian Sandahl 2021-01-18 7 The Kernel ALPHAs Source of picture: Ivar Jacobson International Essence/Kristian Sandahl 2021-01-18 8 Brief explanation Source of picture: Ivar Jacobson International Essence/Kristian Sandahl 2021-01-18 9 The structure of an ALPHA Source of picture: Ivar Jacobson International Essence/Kristian Sandahl 2021-01-18 10 Requirements– one of the alphas What the software system must do to address the opportunity and satisfy the stakeholders. -
The O/R Problem: Mapping Between Relational and Object-Oriented
The O/R Problem: Mapping Between Relational and Object-Oriented Methodologies CIS515 Strategic Planning for Database Systems Ryan Somma StudenID: 9989060874 [email protected] Introduction Relational databases are set of tables defining the columns of the rows they contain, which are also conceptualized as relations defining the attributes of the tuples they store. Relational Database Management Systems (RDBMS) abstract the normalized relational structures underlying the system away from the user, allowing them to focus on the specific data they wish to extract from it. Through queries, they provide users the capability of joining sets in relations into reports, transforming data into information. Through normalization, they eliminate redundancy, ensuring there is only one source for each data element in the system, and improve integrity through relationships based on data keys and validation (Rob and Coronel, 2009). Although there are alternatives to RDBMS‟s, the top five database management systems for 2004 to 2006 were all relational (Olofson, 2007). Object orientation is a “set of design and development principles based on conceptually autonomous computer structures known as objects.” Object-oriented programming (OOP) takes related data elements and functions, known as properties and methods, and encapsulates them into objects that may interact with other objects via messaging or act upon themselves. This strategy reduces complexity in the system, hiding it within objects that are easier to understand as concepts rather than exposing their workings within a morass of procedural code. Additionally, OOP promotes reuse of coding solutions with classes, which are built to model a generalized set of properties and methods that are implemented in object instances, which reuse the class code. -
Practice to Perfect: the Quality First Model
Editor: Bertrand Meyer, EiffelSoft, 270 Storke Rd., Ste. 7, Goleta, CA 93117; voice (805) 685-6869; [email protected] It’s the spiral model. Barry Boehm’s great contribution (“A Spiral Model of Practice Software Development and Enhance- ment,” Computer, May 1988) was to emphasize the need to handle risk in soft- Object Technology ware project management. But Quality To Perfect: First does not use spiral’s idea of repeated analysis-design-implementation cycles. It builds the software, cluster by cluster, using a seamless, reversible process, The Quality as described by Kim Walden in this column (“Reversibility in Software Engineering,” Sept. 1996). First Model It’s just.... Probably not. Few basic ideas are completely new in software; to a certain extent, all had been said in 1974 Bertrand Meyer, EiffelSoft by Edsger Dijkstra, Tony Hoare, Knuth, Harlan Mills, Niklaus Wirth, and a few Ich bin der Geist, der stets verneint, I’ve always worked that way. If that’s others. What counts is how you put the und das mit Recht Mephistopheles really true, congratulations. But I’d like to basic ideas together: what you do, and – Goethe’s Faust, part I (for the trans- see it before I believe it, because some as- also what you don’t do. lation, read on) pects of this process go directly against con- ventional ideas of software development. It’s a personal software process and will not work for large developments. Large aving recently completed a mul- It’s just literate programming. Donald developments are aggregates of personal tiyear writing project, I now Knuth’s literate programming is a great processes, as described by Watts have time to program again. -
Teaching Devops in Academia and Industry: Reflections and Vision
Teaching DevOps in academia and industry: reflections and vision Evgeny Bobrov1, Antonio Bucchiarone3, Alfredo Capozucca2 Nicolas Guelfi2, Manuel Mazzara1, Sergey Masyagin1 1 Innopolis University, Russian Federation 2 University of Luxembourg 3 Fondazione Bruno Kessler, Trento, Italy Abstract. This paper describes our experience of delivery educational programs in academia and in industry on DevOps, compare the two ap- proaches and sum-up the lessons learnt. We also propose a vision to implement a shift in the Software Engineering Higher Education curric- ula. 1 Introduction DevOps is a natural evolution of the Agile approaches [1,2] from the software itself to the overall infrastructure and operations. This evolution was made pos- sible by the spread of cloud-based technologies and the everything-as-a-service approaches. Adopting DevOps is however more complex than adopting Agile [3] since changes at organisation level are required. Furthermore, a complete new skill set has to be developed in the teams [4]. The educational process is therefore of major importance for students, developers and managers. DevOps way of working has introduced a set of software engineering activities and corresponding supporting tools that has disrupted the way individual devel- opers and teams produce software. This has led both the world of research and industry to review software engineering life-cycle and all the supporting tech- niques to develop software in continuous operation and evolution. If we want to enclose DevOps in one word, it is continuous. Modelling, integration, testing, and delivery are significant part of DevOps life-cycle that, respect to enterprise or monolithic applications developed some years ago, must be revised contin- uously to permit the continuous evolution of the software and especially an easy adaptability at context changes and new requirements. -
Object- Oriented Software Composition
Oscar Nierstrasz and Dennis Tsichritzis, Object-Oriented Software Composition, Prentice Hall, 1995. Reproduced with the permission of the Publisher, Prentice Hall (a Pearson Education company). This work is protected by copyright and may not be reproduced other than when downloaded and viewed on a single Central Processor Unit (CPU) for private use only. It is not otherwise to be reproduced or transmitted or made available on a network without prior written permission of Prentice Hall. All other rights reserved. Object- Oriented Software Composition EDITED BY Oscar Nierstrasz UNIVERSITY OF BERNE AND Dennis Tsichritzis UNIVERSITY OF GENEVA First published 1995 by Prentice Hall International (UK) Ltd Campus 400, Maylands Avenue Hemel Hempstead Hertfordshire, HP2 7EZ A division of Simon & Schuster International Group © Prentice Hall 1995 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form, or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission, in writing, from the publisher. For permission within the United States of America contact Prentice Hall Inc., Englewood Cliffs, NJ 07632 Printed and bound in Great Britain by T.J. Press (Padstow) Ltd, Padstow, Cornwall. Library of Congress Cataloging-in-Publication Data Object-oriented software composition / edited by Oscar Nierstrasz and Dennis Tsichritzis. p. cm.—(The Object-oriented series) Includes bibliographical references and index. ISBN 0-13-220674-9 1. Object-oriented