36 research outputs found
A Constraint-based Model for Multi-objective Repair Planning
This work presents a constraint based model for the
planning and scheduling of disconnection and connection
tasks when repairing faulty components in a system.
Since multi-mode operations are considered, the
problem involves the ordering and the selection of the
tasks and modes from a set of alternatives, using the
shared resources efficiently. Additionally, delays due to
change of configurations and transportation are considered.
The goal is the minimization of two objective functions:
makespan and cost. The set of all feasible plans
are represented by an extended And/Or graph, that embodies
all of the constraints of the problem, allowing non
reversible and parallel plans. A simple branch-and-bound
algorithm has been used for testing the model with different
combinations of the functions to minimize using the
weighted-sum approach.Ministerio de Educación y Ciencia DIP2006-15476-C02-0
Conformance checking and diagnosis for declarative business process models in data-aware scenarios
A business process (BP) consists of a set of activities which are performed in coordination in an organizational
and technical environment and which jointly realize a business goal. In such context, BP management
(BPM) can be seen as supporting BPs using methods, techniques, and software in order to design,
enact, control, and analyze operational processes involving humans, organizations, applications, and
other sources of information. Since the accurate management of BPs is receiving increasing attention,
conformance checking, i.e., verifying whether the observed behavior matches a modelled behavior, is
becoming more and more critical. Moreover, declarative languages are more frequently used to provide
an increased flexibility. However, whereas there exist solid conformance checking techniques for imperative
models, little work has been conducted for declarative models. Furthermore, only control-flow perspective
is usually considered although other perspectives (e.g., data) are crucial. In addition, most
approaches exclusively check the conformance without providing any related diagnostics. To enhance
the accurate management of flexible BPs, this work presents a constraint-based approach for conformance
checking over declarative BP models (including both control-flow and data perspectives). In addition,
two constraint-based proposals for providing related diagnosis are detailed. To demonstrate both
the effectiveness and the efficiency of the proposed approaches, the analysis of different performance
measures related to a wide diversified set of test models of varying complexity has been performed.Ministerio de Ciencia e Innovación TIN2009-1371
Diagnosing Errors in DbC Programs Using Constraint Programming
Model-Based Diagnosis allows to determine why a correctly
designed system does not work as it was expected. In this paper, we propose
a methodology for software diagnosis which is based on the combination
of Design by Contract, Model-Based Diagnosis and Constraint
Programming. The contracts are specified by assertions embedded in the
source code. These assertions and an abstraction of the source code are
transformed into constraints, in order to obtain the model of the system.
Afterwards, a goal function is created for detecting which assertions or
source code statements are incorrect. The application of this methodology
is automatic and is based on Constraint Programming techniques.
The originality of this work stems from the transformation of contracts
and source code into constraints, in order to determine which assertions
and source code statements are not consistent with the specification.Ministerio de Ciencia y TecnologÃa DPI2003-07146-C02-0
Constraint satisfaction techniques for diagnosing errors in Design by Contract software
Design by Contract enables the development of more reliable
and robust software applications. In this paper, a methodology
that diagnoses errors in software is proposed. This
is based on the combination of Design by Contract, Modelbased
Diagnosis and Constraint Programming. Contracts
are specified by using assertions. These assertions together
with an abstraction of the source code are transformed into
constraints. The methodology detects if the contracts are
consistent, and if there are incompatibilities between contracts
and source code. The process is automatic and is
based on constraint programming.Ministerio de Ciencia y TecnologÃa DPI2003-07146-C02-0
A Constraint-based Job-Shop Scheduling Model for Software Development Planning
This paper proposes a constraint-based model for the Job
Shop Scheduling Problem to be solved using local search techniques.
The model can be used to represent a multiple software process planning
problem when the different (activities of) projects compete for limited
sta®. The main aspects of the model are: the use of integer variables
which represent the relative order of the operations to be scheduled, and
two global constraints, all different and increasing, for ensuring feasibility.
An interesting property of the model is that cycle detection in the sched-
ules is implicit in the satisfaction of the constraints. In order to test the
proposed model, a parameterized local search algorithm has been used,
with a neighborhood similar to the Nowicki and Smutnicki one, which
has been adapted in order to be suitable for the proposed model.Ministerio de Educación y Ciencia DIP2006-15476-C02-0
Automating correctness verification of artifact-centric business process models
Context: The artifact-centric methodology has emerged as a new paradigm to support business process
management over the last few years. This way, business processes are described from the point of view
of the artifacts that are manipulated during the process.
Objective: One of the research challenges in this area is the verification of the correctness of this kind of
business process models where the model is formed of various artifacts that interact among them.
Method: In this paper, we propose a fully automated approach for verifying correctness of artifact-centric
business process models, taking into account that the state (lifecycle) and the values of each artifact
(numerical data described by pre and postconditions) influence in the values and the state of the others.
The lifecycles of the artifacts and the numerical data managed are modeled by using the Constraint
Programming paradigm, an Artificial Intelligence technique.
Results: Two correctness notions for artifact-centric business process models are distinguished
(reachability and weak termination), and novel verification algorithms are developed to check them.
The algorithms are complete: neither false positives nor false negatives are generated. Moreover, the
algorithms offer precise diagnosis of the detected errors, indicating the execution causing the error where
the lifecycle gets stuck.
Conclusion: To the best of our knowledge, this paper presents the first verification approach for
artifact-centric business process models that integrates pre and postconditions, which define the
behavior of the services, and numerical data verification when the model is formed of more than one
artifact. The approach can detect errors not detectable with other approaches.Ministerio de Educación y Ciencia TIN2009-1371
Using Distributed CSPs to Model Business Processes Agreement in Software Multiprocess
A business process consists of a set of activities which are performed in a coordination way to obtain an objective. Sometimes the definition of this objective using only a classic business processes management is not possible. When the choreography of the processes cannot be defined with a combination of tasks using sequences, conditions, ’xor’, ’or’ and ’split’ control flow patterns, another representation and solution are necessary to be used. This problem makes difficult the decision making in software management projects. In this paper a way to describe a process agreement is described where the execution and the number of tasks execution order of the Web Services cannot be defined. As a case study, the resource distribution in a multiproject development environment is used. In this case, the processes have to achieve an agreement in function of the business rules that relate the processes. In order to achieve this objective, the Distributed Constraint Satisfaction Problems are used to model and solve this type of problemsJunta de AndalucÃa P08-TIC-04095Ministerio de Ciencia y TecnologÃa TIN2009-1371
Contract-based Diagnosis for Business Process Instances using Business Compliance Rules
In order to increase the quality of business pro cesses when they are automated, the correctness
of the activities can be checked by means of an
analysis of the corresponding business compli ance rules. By analyzing the trace of an instance
of a business process, it is possible to detect the
correctness of the process and to determine which
activity is faulty. Each activity or set of activities
is related to a set of business compliance rules,
which work as contracts that the activities must
satisfy throughout the dataflow.
In order to diagnose a business process instance,
not all the activities participate in every single
execution, since there are control flows that per mit the execution of several branches for a varied
number of times. We propose to automate the di agnosis of these executions of a business process
taking into account the involved activities and
their business compliance rules. Our main contri butions are related to the construction of the cor responding framework using several techniques
related to the constraint programming paradigm
to obtain the incorrect activities. The two differ ent proposals consider the tradeoff between the
obtaining of the minimal diagnosis and the per formanceJunta de AndalucÃa P08-TIC-04095Ministerio de Ciencia y TecnologÃa TIN2009-1371
Constraint-Driven Approach to Support Input Data Decision-Making in Business Process Management Systems
A business process consists of a set of activities that are performed in coordination in an organizational and technical environment (Weske 2007). The base of business process management systems (BPMS) is the explicit representation of business processes with their activities and the execution constraints between them. Compliance rules represent a natural step to include requirements between business functionality and data. For the design of a whole business process management (van der Aalst et al. 2003), it is necessary to design the model of activities and define the causal and temporal relationships between them (Walzer et al. 2008). Compliance rules can help to complete this information, since they can be used to validate business data (Chesani et al. 2008).Junta de AndalucÃa P08-TIC-04095Ministerio de Ciencia y TecnologÃa TIN2009-1371
Computing alignments with constraint programming : the acyclic case
Conformance checking confronts process models with real
process executions to detect and measure deviations between modelled
and observed behaviour. The core technique for conformance checking
is the computation of an alignment. Current approaches for alignment
computation rely on a shortest-path technique over the product of the
state-space of a model and the observed trace, thus suffering from the
well-known state explosion problem. This paper presents a fresh alternative
for alignment computation of acyclic process models, that encodes
the alignment problem as a Constraint Satisfaction Problem. Since modern
solvers for this framework are capable of dealing with large instances,
this contribution has a clear potential. Remarkably, our prototype implementation
can handle instances that represent a real challenge for current
techniques. Main advantages of using Constraint Programming paradigm
lie in the possibility to adapt parameters such as the maximum search
time, or the maximum misalignment allowed. Moreover, using search and
propagation algorithms incorporated in Constraint Programming Solvers
permits to find solutions for problems unsolvable with other techniques.Ministerio de EconomÃa y Competitividad TIN2015-63502-C3-2-RMinisterio de EconomÃa y Competitividad TIN2013-46181-C2-1-