=Paper=
{{Paper
|id=Vol-1/paper-13
|storemode=property
|title=OLSEN: an object-oriented formalism for information and decision system design
|pdfUrl=https://ceur-ws.org/Vol-1/guetari-et-al-long.pdf
|volume=Vol-1
|authors=R. Guetari,F. Piard,B. Schweyer
}}
==OLSEN: an object-oriented formalism for information and decision system design==
https://ceur-ws.org/Vol-1/guetari-et-al-long.pdf
OLSEN: An Object-Oriented Formalism for
Information and Decision System Design
Ramzi Guetari, Frédéric Piard 1 , Bettina Schweyer2
LLP/CESALP 41 Avenue de la Plaine
BP. 806 - 74016 Annecy Cedex - FRANCE
Tel : (+33) 50.66.60.80 - Fax : (+33) 50.66.60.20
email : guetari|piard|schweyer@esia.univ-savoie.fr
1 CIFRE contract with ANRT and Pôle Productique Rhône-Alpes
2 CIFRE contract with ANRT and ARM Conseil
- an industrial information database, where products,
1.ּIntroduction resources, machines,… are described.
The Object oriented model has spread widely within - Consumer-Supplier Information Systems (CSIS). A
programming languages during the last years. The CSIS stands for an “atom” of organisation. It is a
principles of this model have had a great influence on generalisation of the customer-supplier exchange
analysis and design techniques. However no existing relationship to every couple of actors in the
method is able to manage the whole analysis- enterprise (men, machines, software). Every CSIS
specification-design-implementation cycle, preserving is associated to an objective, transforms resources
the homogeneity of the model used in different stages and emits a satisfaction level.
and the coherence by passing from one stage to the - an Objective Management System (OMS), whose
following. role is to create a graph from expressed objectives,
We think that the global management of the life cycle where every node is an objective associated to a
cannot be solved, with the existing state of knowledge, CSIS.
by one unique miraculous method, which could adapt - a Resource Management System (RMS), in charge
to every kind of application. We think on the contrary of the product and resource management and
that the problem should be treated by a panel of sharing.
methods dedicated to a particular domain. - an activation system (AS), producing actions plans
For this reason we have developed the OLYMPIOS to organise processes, taking into account the
model at the LLP-CESALP laboratory. This model application, temporal constraints, and
covers the life cycle of every application in the field of communications/synchronisation between CSIS.
Information and Decision Systems for Manufacturing
Firms. OLYMPIOS uses algebraic techniques, 3.ּThe IDS Life Cycle
transformation rules and a predefined entity The OLYMPIOS model covers the different stages of
organisation to propose an original approach for object the IDS life-cycle (Fig.ּ1). We use an algebraic
oriented design of information and decision system. approach for the four facets of industrial information so
as to obtain a coherent (i.e. sufficiently complete and
2.ּOLYMPIOS Model Concepts. consistent) specification. The design stage enables us to
The information processed in an enterprise, which we design the information system from specification and
call industrial information, is a complex datum. An by analysing the "existing" system of the enterprise and
information and decision system (IDS) must take this its objectives. The result of this stage is a representation
complexity into account. We propose to represent of the IDS using structured entities. The OLYMPIOS
industrial information through four main facets : model introduces the uniformity of the model used
from specification up to design. It uses tools proving
- data, describing the different entities handled by the the coherence of the system in the specification step
IDS and the actions that they can perform or can be and maintaining this coherence by automating the
subjected to ; translation from one stage to another.
- temporal properties of the different kinds of
processes (including traceability of information) ; 3.1.ּAnalysis Stage
- organisation, considered through information flows;
In the analysis stage, the relevant information for the
- economic facet, which describes the means of
data, the temporal, the organisational and the economic
performance evaluation in relation to enterprise
facets is collected.
environment and objectives.
The result of the data facet analysis consists in the
The OLYMPIOS model [Beauchêneּ93] [BHPּ93]
description of the data handled (resources etc.) in the
[BHSּ93] covers the different stages of such a system
system to design and, for each datum, the set of
life cycle and proposes original solutions for its
operations that can be realised (data dictionary). This
analysis, specification, design and realisation.
static description can be translated into a finite state
OLYMPIOS describes activities, taking into account
automaton in which every node represents a state of the
the assigned objectives and the resources availability.
datum in question and every edge an operation which
The basic modelling elements areּ:
produces a new state.
The analysis of the organisational aspects of the stage. This automatic construction is realised by the
manufacturing firm results in a set of interactions algorithms [Nkongoּ90] developed in our laboratory.
between the different agents of the enterprise in the
form of exchange relationships. By interviewing each 3.2.2.ּOrganization Specification
of these agents we enumerate, on the one hand, the It starts from the analysis of the "existing system",
exchange relationships in which he is consumer, i.e. which results (inter alia) in the identification of actors
follows a certain objective by asking for satisfaction of and their functions and objectives. Specifying
the respective needs, and on the other hand, we identify organisation consists in formally expressing identified
the relationships in which he is supplier and performs a objectives (in the "triple" form), and in constructing
certain function. For each of these functions (which we their associated CSIS from standard parametrized
would like to call basic operation) he enumerates the ASAT of organisation [Beauchêneּ93]. Simultaneously,
resources necessary for realising this operation and the one must elaborate the different graphs of objectives.
algorithm he follows to obtain the wanted resource.
Thus, this interview gives us information about 3.2.3.ּTemporal Specification
- objectives and their decomposition, The specification of the industrial information temporal
- identification of the possible suppliers for the facet uses a synchronous process algebra, directly
realisation of a given objective, derived from the SCCS calculus of R. Milner
- the basic operations that can be performed and [Piardּ93]. We specify four kinds of processes with this
knowledge about how to execute the operations and language :
which resources are needed. 1- chronological and event-based clocks, essential to
Starting from this information, we can establish a specify synchronisation and to measure temporal
knowledge base of the different ways to decompose intervals;
objectives and a knowledge base for the needed 2- behaviours of data facet entities, which are not
resources for each basic operation. These knowledge completely determined by ASAT axioms;
bases will help us, in addition to the predefined 3- behaviours of CSIS;
structure of such an exchange relationship, to define the 4- activation plans, elaborated by the activation system
enterprise organisation. from graphs of objectives and resources to schedule
the CSIS.
The analysis of the temporal facet provides a dynamic
description of the system. It enables us to describe the Existing System Analysis
temporal behaviour of different agents and resources of
the system and their interactions. For this part of the Objectives Description
ASAT Temporal
analysis, a method close to natural language is being Base of Entities Analysis
developed which will allow a user-friendly way of by automata
Rules for
describing temporal rules. Objectives Behaviours
From this analysis we also obtain a description which management
ASAT Generator
we call realization programs. These programs contain
the description of the CSIS functionning and of the
Generator AS
CSIS SCCS Description of
operations which are not formally describable. Entities temporal
generator Generated
ASAT behaviour
As far as the economic facet is concerned, we are
actually working on an interview structure including OMS RMS Class
fuzzy logic in order to acquire the information Generator
necessary for evaluating the system's performance.
3.2.ּSpecification Stage Standard
Classes
3.2.1.ּData Specification
The data facet corresponds to the IDS functional and
structural aspects, and aims at representing the OLSEN
technical and technological data. We use Algebraic Resources
Generator
Specifications of Abstract data Types (ASAT) Affectation
[Guttagּ78] [Jacquenetּ86] [Liskovּ87] so as to have CSIS OLSEN Realization
efficient and simple proof techniques at our disposal. program
Resources
An ASAT enables us to express an entity behaviour in a CSIS A CSIS B CSIS C Closing Down
high level formalism. For a given entity, an ASAT is a
triple <Ω,Σ,A>, where Ω is a set of domains containing
the domain of the entity values, Σ is a set of operations
on the entity, and A is a set of equations (axioms and
Users Application Data
preconditions) on these operations, which determines Procedures
Interfaces Programs Bases
the entities behaviour and the relationships between
them. ASAT are automatically constructed from the
entities automata, which are the result of the analysis Fig. 1. The Analysis - Specification - Design Cycle in the
OLYMPIOS Model
The construction of left parts of axioms :
3.2.4.ּEconomic Specification The construction of axioms left parts consists of
This facet cannot be specified independently of data building the following sets :
and organisation. Indeed it is shared between them, and - CT = {c(y*), c @ C}
the most important part is included in the organisation - OT = {o(x, y*), o @ O, x @ CT}
facet. Works are still going on to sharpen the economic - ST = {s(x, y*), s @ S, x @ CT}
view of OLYMPIOS on the information system (with OT and ST contain the left parts of specification
the help of performance indicators, fuzzy logic and axioms. Axioms which define the semantic of the
project-based management approach). abstract data type have their left parts in the OT set and
axioms which shows the simplification of terms of
3.3.ּDesign Stage T(Ω,Σ) have their left parts in the ST set.
The OLYMPIOS model, in its design stage, is based on
the class model. This model was extended in order to The construction of right parts of axioms :
allow to take all industrial information features into The graph of states, whose every node is a state of
account, in particular real time ones. The result of the entities of TI type, and whose every transition is an
design stage is an organisation of entities independent operation, providesּ:
of possible target programming languagesּ: OLSEN
(OLympios Structured ENtity). 1- Ω = {TI, STATES}, STATES = {E1,E2,E3,...}
An OLSEN [Guetariּ94] is composed of a “class” part 2- Σ = {state, σ1, σ2, σ3, ..., σn} = O+C+S, T = S + C
and another part called “scenario” which indicates the = {σ1, σ2, σ3, ..., σn} is the set of operations which
interactions with its environment. The difference create or transform the values of TI (represented in
between an OLSEN and a classical object is the the automata by transitions), O={state} contains a
scenario which describes the temporal behaviour single observer.
generally missing in the standard class model. The 3- Left parts of axioms by the building of AC,AO,AT
OLSEN model is a “design object”. from O,C et T.
In this paper, we present only the specification and 4- Right parts (y) of axioms in the form state(c(x*)) =
design of Activation System (AS part) and Resource y, where c@ C, and y is the expression of the name
Management System (RMS). The Objective of the node extremity of the path represented by
Management System is the subject of a publication to c(x*) from the starting state. If there are many of
come. these paths then the y term will be expressed in the
form if...then...else ...
4.ּThe Transition from the Analysis to the 5- Right parts (y) of axioms in the form s(c(x*)) = y,
where s @ S is a convertible operation and y
Specification Stage corresponds to the canonical form of the state
This stage consists in describing data types using finite extremity of the path c(x*), i.e. the expression of
state automata. We must first insist on the fact that the shortest path between the starting state and the
every entity cannot be described by an automaton. Only state extremity of the path represented by the
if it has successive states and if it is concerned by expression c(x*). In other terms, these axioms are
actions passing from one state to another can it be represented in the automata by simple circular
described by an automaton. We do not use the automata paths. If there are many of these paths then the y
as a specification tool but as a tool allowing us to shape term will be expressed in the form if...then...else ...
the evolution of some kind of data type over a set of 6- Preconditions related to the state of arguments
states. In this kind of automata, each transition (membership of TI) of each operation, which are
represents an operation changing the entity's state and expressed by the restrictions on the domain of this
each node represents one state of the entity. The operation before its execution. These restrictions
automata may have many transitions corresponding to are issued from the state origin of the arc
the same operation, however, each state is unique. A representing the operation.
particular state called “starting state” must always exist.
It corresponds to the extremity of the transition which
stands for the operation creating the type of 5.ּThe Transition from the Specification to
interestּ(TI). the Design Stage
The entities described by automata are distinguishable The transition from the specification stage (ASAT and
by the successive states that they can have. The order in SCCS) to the design stage is done automatically in two
which different states are occupied is well defined. The steps. The first step consists in taking the ASAT one by
graph of state changing is oriented and has a starting one and translating each one into a standard class. The
state from which we can observe the evolution of the second step is a global one and permits the organization
entity. This graph allows us to distinguish the of the communication between the obtained classes.
constructor operations using a single method. The The benefit of this automation is the preservation of the
transitions corresponding to these operations have coherence obtained in the specification stage.
extremity nodes which can be reached from the starting
state by only one path of the graph. The construction of 5.1.ּThe Standard Class Generation
axioms is done in two stepsּ: the construction of left The class attributes and methods are generated from the
é
parts of axioms and the construction of right parts of ASAT operations. This is done using the following
axioms, as it is shown belowּ: rules. We note an operation : σ : Ω 1 Ω2. Ω1 is the
set of domains and Ω 2 is the set of codomains. “TI” is The OLSEN formalism helps us to generate data bases
the data type that we specify. We distinguish three on the realization stage. The application programs are
kinds of operations : obtained through the OLSEN, the realization programs
and the CSIS organization.
- Case 1 : σ : Ω 1 é Ω 2 / TI # Ω 1 and Ω 2 = {TI}. If we target object-oriented data bases in the realization
This kind of operation corresponds to a particular stage, we have to use the OLSEN and the realization
constructor. For each constructor, we generate a programs. In this case, each class part of an OLSEN is
method “New” with parameters of type Ω1. directly translated into a data base object and the
- Case 2 : σ : Ω1 é Ω2 / Ω1 = {TI} and Ω2 = {ω ≠ scenario part is used for the data access in the
TI}. This kind of operation corresponds to application programs. The realization programs allow
observers. The class structure is obtained from these us to implement the methods of the data base objects.
observers. For each observer we generate an If the data bases are not object-oriented, only the
attribute of type Ω2 and a method to access it. structure of the OLSEN interferes for the realization of
- Case 3 : σ : Ω1 é Ω 2 / TI @ Ω 1 and TI @ Ω2. This these data bases. In a relational data base, for example,
case corresponds to a general one. For each the OLSEN structure is used for the table creation. The
operation of this kind we generate a method with in inheritance relationship is eliminated in these data
parameters of type ω @ Ω1 / ω ≠ TI and out of bases and replaced by the result of merging the
parameters of type ω @ Ω2 / ω ≠ TI. structures of a super-class and the sub-classes.
The scenario of an OLSEN is issued from SCCS In the realization stage we can obtain three different
formulae. An SCCS formula contains several types of CSIS translations: automatic CSIS where the
deterministic parts. Each part provides one script in the actors perform totally automated processes, semi-
OLSEN scenario. The scenario generation is done in automatic CSIS where one of the two actors performs
three steps : the first two provide the declarative part of an automated task or the manual CSIS where both
a scenario, the third one provides the dynamic part. For actors perform manual tasks.
each OLSEN, we determine the determinist parts of the
corresponding BEHAVIOUR (separated by a “sum” The first type of CSIS with the realization programs
operator). For each part, we execute the following three and the scenarii allow us to obtain the application
stepsּ: programs. These programs will act upon the data bases
with the classical operations like add, modify and
• Event Detection. This step permits the detection delete. These interactions with the data base are
and declaration of the different kinds of events. The performed through message sending between the data
type of each event is deduced from the SCCS base objects in the case of an object-oriented data base
syntax. A communicational event appears in at least or through primitives which are the result of the
two BEHAVIOURs, once preceded by the delay OLSEN behaviour in the case of non object-oriented
operator δ, and once without this operator. An data bases.
environmental event is identified by the existence The semi-automatic CSIS form the interactions
of a clock emitting this event. An event is between a user and a process. These CSIS lead towards
conditional if its complementary event appears at the implementation of user interfaces and external
least once in a BEHAVIOUR. When all events are views which restrict the data base access according to
declared, we proceed to the unification of the the user's rights.
communicational events. This unification is based The manual CSIS finally, allow us to realize the manual
on the observational equivalence [Austryּ84] and procedure for which the automation would be too
consists of giving the same name to two expensive.
synchronously successive events in a SCCS
formula. 7.ּConclusion
• Identification of the Set of Suppliers. For each The OLYMPIOS model provides the means to analyse
communicational event, we define its receiving and specify coherently an industrial information and
OLSENs whose BEHAVIOURs contain this event, decision system. It allows then to design the specified
preceded by the delay operator δ. Any OLSEN IDS by preserving the coherence obtained in the
responding to this event by applying one of its specification stage by using algebraic techniques. The
methods must be added to the suppliers list of the continuity and uniformity claimed by the Olympios
treated OLSEN. model is the result of two factorsּ:
• Script Generation. A script is generated for each - the use of algebraic tools to specify all the compo-
determinist part. Each event described in the
formula is replaced by one or several simultaneous nents of an IDS like the data facet, the organization
dispatches of messages. The receivers of these facet or the temporal facet,
messages are the suppliers defined in step 2. - the use of ASAT to specify data and Objects to
design them.
6.ּThe Transition from the Design to the
This care of continuity and uniformity has lead us to
Realization Stage develop algorithms (and parts of a future CASE-Tool)
This transition is based on the realization programs to automatically generate a coherent OLSEN
which we have obtained in the analysis stage.
organisation from the analysis. Our objective is to
generate a maximum of code for applications.
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