Introduction to the
Method
About TIMe - The Integrated Method
The Integrated Method (TIMe)
is not just a
method
, but a
Methodology
, meaning a collection of methods and languages with guidelines for when
to use them. We call it The Integrated Method only to keep the name short.
TIMe recommends a combination
of
languages
and
notations
that may be used to analyze, model and ultimately build systems. These
are:
-
UML - The Unified Modeling Language [146],
-
SDL - Specification and Description Language
[102],
[108]and
-
MSC - Message Sequence Charts [110].
In this respect, TIMe integrates
these languages and notations. But the foundation of TIMe is independent
of these languages, which means that the future of TIMe is not highly dependent
on the future of these languages.
-
a set of system development activities that covers
most of the system development process, with emphasis on the activities
leading up to implementation,
-
guidelines on object and property modeling in
general, and particularly how to do it in UML / SDL and MSC respectively,
and
-
tutorials in UML, SDL and MSC.
Object oriented
TIMe is truly object oriented
in its approach. It defines its own underlying object and property models,
and contains detailed guidelines on:
-
how to make analysis object models using Unified
Modeling Language (UML),
-
how to make design object models using Specification
and Description Language (SDL), and
-
how to make interaction property models and Use
Cases using Message Sequence Charts (MSC).
TIMe is characterised by:
Abstract models
-
Emphasis on abstract models and descriptions:
Abstract descriptions leave out implementation specific details and let
the developers focus on functionality.
Property models
-
Focus on (external) properties : Objects
are the building material from which systems and components are constructed.
Property descriptions are used at an early stage of development to express
the properties required from a system or an object. At a later stage they
are used to express the properties actually provided by a system or component.
Service orientation
-
Users tend to think in terms of services and
interfaces. Therefore TIMe recommends use of separate property models for
services and interfaces. These models are used for high level service engineering,
and for sythesising object designs that provide the services.
Roles
-
Strong object-property relationships :
Roles are used to describe properties, and are related to object designs
by projection. Roles are used to link properties and objects. Projections
are used for synthesis of new objects and for documenting existing objects.
Design for reuse
-
Planned variability and reuse :
TIMe seeks to make generic system families which may be adapted
as easily and safely as possible to the needs of particular systems. Components
for reuse across families come from general domain descriptions. TIMe describes
a cost-effective way to define instantiation of particular systems by defining
the general parts by reference to the family description, detailing only
what is special for that particular occurrence, i.e. its configuration.
Synthesis
-
Design synthesis : Property oriented design
involves:
Decomposing required service
and interface properties into object properties.
Synthesizing object designs
from required object properties, by transformation and by composition,
taking reuse into account.
Comparing properties: required
against provided (validation).
Design with reuse
TIMe is centered around
a set of models and descriptions capable of expressing domain knowledge,
specifications in terms of external properties, system designs in terms
of structure and behaviour, implementation mappings and system instantiation
Like most other similar
methods, TIMe distinguishes between Analysis, Design, Implementation and
Instantiation (see
Figure
1).
-
Figure 1: TIMe activities, descriptions
and languages
-
Open
figure
The distinction between
Domain and System Design is not particular for TIMe. What is special, however,
is that:
-
design is split between
application design
, where the functionality of the system is design,
architecture design
, where the non-functional properties are taken care of, and
framework design,
that defines types of systems with the same infrastructure (e.g. supporting
distribution) where the application specific parts are singled out to be
redefinable in specific systems.
-
the complementary object models and property
models are used both for domain and system analysis, and for design.
There are several ways to
learn The Integrated Method:
-
By reading. Enter the TIMe
at a glance theme; read it on-line or print
it out and read it on paper.
-
By example. Enter the Examples
theme and see how the methodology works on a practical example. A complete
worked example of descriptions and documents as they appear at various
stages of development is presented there.
-
By process. Enter the Process
models theme, and see how activities may be invoked and descriptions
evolved.
-
By activity. Enter the Activities
and Descriptions theme and learn about the activities and descriptions,
and their rules and guidelines.
These ways complement each
other and are systematically linked.
-
Figure 2: Methodology overview
-
Open
figure
Themes
The main themes of TIMe
are:
-
Introduction
to the Method , which is the theme you are reading just now.
-
Introduction
to the Book , which tells you how to use the media.
-
TIMe
at a glance , which gives a first introduction to the Methodology.
We recommend that this be read next.
-
Foundation
of TIMe , which deals with underlying principles of TIMe.
-
Activities
and Descriptions , which details all the main activities that are
performed when developing systems using the Integrated Methodology, and
which descriptions should be produced at the different levels of abstraction.
Practical guide lines and strategies are provided all the way from domain
analysis to system implementation.
-
Process
models , which presents the "project management" view, showing
how the various activities are performed and how the descriptions evolve
in the context of real projects.
-
Examples
. A comprehensive example is used to illustrate the various descriptions
and how they are developed and evolve.
-
Object
and Property models presents the languages used for expressing
object models and property models, and how to align the two.
-
Language tutorials for UML,SDL
and MSC (MSC 92 and MSC96).
-
Verification
and Validation deals with the corrective quality assurance activities.
-
Process
Improvement deals with the introduction of TIMe into a company
and later process monitoring and improvement.
-
Metrics
deals with the measurement of the development process.
-
Configuration
Management deals with the handling of evolving software components
TIMe Electronic
Book
It is our experience that
a methodology book is used in several ways that are somewhat conflicting:
-
as a textbook to be read from the start to the
end;
-
as a quick reference to language issues;
-
as a source of examples and design solutions;
-
as a source of templates for specific descriptions;
-
as a guide to process improvement;
-
as a concise methodology handbook.
Using an electronic medium
using hyperlinks we hope that all these needs may be satisfied.
Read the theme
Introduction
to the Book to learn more about how to use the material on-line,
and how to print any or all parts of the book.
The
SISU project
TIMe was initially conceived
in the SISU project, which was a Norwegian technology transfer program
aiming to improve the productivity and the quality of Norwegian companies
that develop systems within the real-time domain.
The project started in 1988
and ended in 1996, and involved some 20
Partners
from industry (including Alcatel, Ericsson and Siemens) and research institutes,
including the Norwegian Computing Center (that natured Simula in the `70's)
and SINTEF.
The project has contributed
to higher profitability in the participating companies by increasing the
their capability to achieve:
-
right system quality
-
shorter time to marked
-
reduced development costs
-
improved project control
To achieve these goals the
project focused on:
-
System descriptions
-
Verification and Validation
-
Transformations
-
Configuration and reuse
-
Process improvement
Object oriented SDL (SDL-92)
The project has been active
in the development of the object oriented extensions to SDL that became
part of the language in the 1992 version of Z.100 (popularly called SDL-92)
[102].
It also contributed to the Methodology Guidelines for SDL (appendix I to
Z.100)
[104].
MSC-96
The project participated
in the MSC development within ITU, including the structural concepts that
became part the 1996 version of MSC (popularly called MSC-96)
[110].
Textbook
SISU developed a forerunner
of TIMe, the SISU methodology, which is described in the textbook by Rolv
Bræk and Øystein Haugen:
Engineering Real Time Systems.
An Object-Oriented Methodology using SDL [24].
Presently, some 600 engineers have been through a training course based
on this book, and some 15-20 Norwegian companies use the SISU methodology
actively in their product development. Most of them have tool support for
SDL with code generation.
Web site
For more information about
the results of the project, and to download public reports, visit the SISU
web site at
http://www.sintef.no/sisu
Partners
The following companies
and research institutes have been active participants of the SISU project
(SISU-I and SISU-II):
Alcatel Telecom Norway,
Autronica
CAP Gemini (Computas),
Ericsson Private Networks, Norway,
Ericsson Radar, Norway,
Ericsson Semafor, Norway,
Kjell G. Knutsen,
NFT-Ericsson,
Norapp,
Norsonic,
Scanpower,
Seatex Garex (Garex)
Seem Audio,
Siemens (Norway),
Stentofon,
Trioving,
Tandberg Data Storage,
Telox,
SINTEF,
Norwegian Computer Center (NR).
The Authors
The persons listed below
have directly contributed to this book:
In addition a large number
of people have commented on its contents, and helped clarify our ideas.
These are colleagues of ours, participants of
The
SISU project, and international professionals. We thank you all!
We particularly wish to
thank the people at Ericsson who have helped pilot the methodology, that
worked on the HTML version, and that provided valuable feedback: Tim Papas,
Steinar Lundeberg, Stein Erik Ellevseth, Pål Berg and many others.
On this version, Therese
Nilsen and Per Holager of SINTEF Telecom and Informatics have helped compile
the final version for publication.
Rolv Bræk;
SINTEF Telecom and Informatics
Rolv
graduated from the University of Trondheim, Department of Electrical Engineering
in 1969 and has been working with SINTEF since 1973, where he is Principal
Research Scientist. He is also Professor at the Norwegian University of
Science and Technology in Trondheim (NTNU).
Rolv has been working with
software engineering methodology since the early 70's in close cooperation
with Norwegian industry. One of the most reputed projects was the MAREIK
project in the INMARSAT system 1979-81.
Rolv has been working with
formal description techniques for decades, and fathered the SOM
language and methodology, a parallel development to SDL.
Rolv participated in
The
SISU project, with responsibility for Methodology. He is currently
occupied with introducing TIMe to Ericsson, and is also contributing to
the Z.109 standard for SDL with UML.
Rolv is co-author of Engineering
Real Time Systems - An object-oriented methodology using SDL [24].
Joe Gorman;
SINTEF Telecom and Informatics
Joe
studied Computer Science at the University of Glasgow, where he gained
his Honours Degree in 1977. After working in Scottish Universities, he
started work at SINTEF in 1986.
Joe is involved with contract
research work with Norwegian industry, and in international co-operative
research funded by the European Commission. His main research interests
are software engineering, software development methodologies, compiler
techniques and configuration management.
In The
SISU project Joe was responsible for Configuration Management.
Øystein
Haugen; Ericsson Norway
Øystein
graduated from the University of Oslo in 1980, where he was assistant to
Kristen Nygård for a period.
Øystein worked at the
Norwegian Computing Center for 4 years as project leader for a Simula machine.
From 1984-88 he worked at SimTech, and from 1988-1990 as senior research
scientist at ABB Corporate Research, Norway. Øystein was an independent
consultant while working on his Ph.D., until he joined Ericsson Norway
in 1997 to work on software methods and languages. Øystein is Associate
Professor at the University of Oslo.
Øystein participates
in the standardization work in ITU, first in the development of the object-oriented
extension of SDL that where incorporated in the 1992 version of SDL ("SDL-92")
[102],
and later as Associate Rapporteur for MSC in ITU-T Study Group 10, that
produced the 1996 version of Message Sequence Charts [110].
He is currently Rapporteur for MSC in ITU-T, responsible for the development
of MSC standard year 2000.
Øystein is co-author
of Engineering Real Time Systems - An object-oriented methodology using
SDL [24].
In The SISU project
Øystein had responsibility for Verification and Validation activities.
Birger Møller-Pedersen;
Ericsson Norway
Birger
graduated from the University of Copenhagen in Denmark in 1976.
Birger worked at the Norwegian
Computing Center from 1977 to 1996, where he specialized in object oriented
languages, including designing and implementing compilers for Simula, designing
Beta, and later adding object orientation to SDL.
Birger joined Telenor Research
and Development (the Norwegian PTT) in 1996, where he amongst other things
worked on Java in TMN.
In 1998 Birger joined Øystein
and Geir at Ericsson NorARC, where he has continued his work with TIMe
and SDL. Birger is also Associate Professor at the University of Oslo.
Birger participates in the
standardization work in ITU, first as Associate Rapporteur in the development
of the object-oriented extension of SDL that were incorporated in the 1992
version of SDL ("SDL-92") [102].
He is currently participating in the ITU-T Study Group 10, working on the
next version of the SDL standard scheduled for the year 2000. Birger is
Associate Rapporteur for the harmonization of SDL and UML, in the coming
Z.109 standard.
Birger is co-author of The
BETA Programming Language [123]
and Systems Engineering Using SDL-92 [144].
Geir Melby,
Ericsson Norway
Geir
worked at Telox until 1988, where he acted as manager and consultant. Geir
participated in the development of embedded software systems for industrial
companies and in Telox' own products, that included a run-time support
system for SDL (Telox SDL Tools).
Geir left Telox to lead The
SISU project from 1988 to 1996.
Geir joined Ericsson Norway
in 1996, where he is manager of the Software Engineering Laboratory of
the Norwegian Applied Research Department (Ericsson NorARC).
Richard
Sanders; SINTEF Telecom and Informatics
Richard
graduated from the University of Trondheim, Institute of Informatics in
1984, Mastering in Computer Science and Telematics.
He worked for 3 years as a
consultant with Computas (now a part of CAP Gemini), developing embedded
software for communication systems using SDL/SOM, and working on a CASE
tool for SDL (DASOM).
Richard worked at Stentofon
(now Stento) from 1987 to 1994 as designer and later software manager,
developing a new generation communication exchange, where automatic code
generation from SDL was introduced in 1988, to our knowledge the first
industrial project to do so. Stentofon where participants of The
SISU project from the start.
Richard joined SINTEF in 1994,
where he has been working with development methodology (in The
SISU project and in Mechatronics), and as a UML/MSC/SDL designer
in industry projects. He is currently occupied with introducing TIMe to
Ericsson Norway. Richard also lectures at the University of Science and
Technology in Trondheim (NTNU).
Tor Stålhane;
SINTEF Telecom and Informatics
Tor
graduated from the University of Trondheim, Department of Electrical Engineering
in 1969. He holds a Ph.D. in statistics from the University of Trondheim,
Department of Mathematical Sciences from 1988.
Tor has worked at SINTEF since
1969, specializing in Software Reliability and Process Improvement. Since
1997 he is also a professor at the Stavanger Polytechnic, where he teaches
quality assurance and process improvement in software development.
In The
SISU project Tor was responsible for Software Metrics.
About
TIMe
Copyright
SINTEF 1997, 1998, 1999
No part of this publication
may be reproduced, stored in a retrieval system, or transmitted, in any
form, or by any means, electronic, mechanic, photocopying, recording or
otherwise, without prior permission, in writing, from SINTEF.
For information about commercial
terms or for comments on TIMe, please contact:
N-7465 Trondheim
Norway
Tel: +47 73 59 30 00
Fax: +47 73 53 25 86
e-mail: time@sintef.no
WWW: http://www.sintef.no/time
FrameMaker, FrameReader and
Acrobat are copyright Adobe
Systems Incorporated. The UML logo, OMG, CORBA and IDL are trademarks
of the Object Management Group,
Inc.
Excerpts from the SDL [102],
[108]and
MSC [110]standards
are reproduced after prior authorization by the copyright holder ITU.
The choice of excerpts is entirely our own and, therefore, does not affect
the responsibility of ITU in any way.
Full text of the ITU standards
( [102]
through
[110])
can be obtained from the ITU
Sales Section, Place des Nations, CH-1211 Geneva 20, Switzerland (see
http://www.itu.int/publications
or Tel. +41 22 730 51 11, Fax +41 22 731 51 94, or email sales@itu.int).
About this version
This version 4.0 of the TIMe
methodology is the second commercially available version. The major improvements
compared to version 3.1 are:
-
UML replaces OMT and OMT+-: all examples have
been revised, and a Tutorial on UML has been included
-
The OMT+- Tutorial has been discontinued
-
TIMe HTML version for the parts that are best
suited for on-line use
-
Improved Activities and Descriptions theme
-
Dictionary added
We have put a lot of effort
into this book, but we have not reached what we consider to be a finished
product. There is still a lot of material we want to add, we know that
some material could be presented in a better way, and that there are loose
ends that need to be tied up. There are also technical issues about the
electronic medium we find unsatisfactory.
It is our modest hope, though,
that we have included material that satisfies the majority of our readers,
and that the electronic textbook is found useful. We encourage comments
on content, shortcomings and errors to the
address
above.
Based on feedback from users
and from our own experience in continued introduction in industrial contexts,
we will incorporate new and better material in future versions of TIMe.
Plans for the near future
of the TIMe Electronic Textbook include:
-
Tutorial on Z.109 SDL with UML
-
Revise SDL Tutorial according to coming year
2000 version of Z.100
-
Revise MSC Tutorial according to coming year
2000 version of Z.105
-
TIMe versions
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Second commercial version.
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Internal version for Ericsson.
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First commercial version
from SINTEF.
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SISU L-2001-5 Final delivery
from The SISU project,
distributed to SISU Participants.
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Second version of Electronic
textbook (distributed to SISU Participants).
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SISU L-2001-2 First version
of electronic textbook. Demonstrated at SDL forum in Oslo.
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SISU L-1112-6 Common Method
Description, version 2.
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SISU L-1112-5 Common Method
Description, version 1.
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SISU L-1112-4 First Draft
of Integrated Methodology (in Norwegian).
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ISBN 0-13-034448-6 Engineering
Real Time Systems - An object-oriented methodology using SDL [24].
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About SINTEF
SINTEF is an independent,
not-for-profit research foundation based in Trondheim and Oslo, Norway.
Our role is to encourage innovation and improve competitiveness in Norwegian
industry and public administration. In doing so, we maintain close links
with the technical Universities in Trondheim and Oslo, collaborating on
projects, and sharing equipment and other resources.
SINTEF is not a publicly
funded organisation. A very small part (less than 4%) of our income is
from a public grant; most of our operating revenues arise from contract
research and development work carried out for industry and the public sector
in Norway and elsewhere.
With over 1800 employees
and a turnover of NOK 1.4 billion, SINTEF is Scandinavia's largest independent
research organisation. It is organised into eight separate research institutes,
covering all major scientific areas and industrial sectors.
SINTEF Telecom and Informatics
is an institute in SINTEF. Our R&D work focuses on information and
communications technologies - covering basic technologies as well as applications
of these. We have departments specialising in computer science, systems
engineering & telematics, distributed systems, radio & signal processing,
and acoustics.
Refer to our website www.sintef.no
for further information.