Computer Methods in Applied Mechanics and Engineering, 2009
Numerical integration errors and volumetric locking in the near-incompressible limit are two outs... more Numerical integration errors and volumetric locking in the near-incompressible limit are two outstanding issues in Galerkin-based meshfree computations. In this paper, we present a modified Gaussian integration scheme on background cells for meshfree methods that alleviates errors in numerical integration and ensures patch test satisfaction to machine precision. Secondly, a lockingfree small-strain elasticity formulation for meshfree methods is proposed, which draws on developments in assumed strain methods and nodal integration techniques. In this study, maximum-entropy basis functions are used; however, the generality of our approach permits the use of any meshfree approximation. Various benchmark problems in two-dimensional compressible and near-incompressible small strain elasticity are presented to demonstrate the accuracy and optimal convergence in the energy norm of the maximumentropy meshfree formulation.
A novel maximum-entropy meshfree method that we recently introduced in Ortiz et al. (2010) [1] is... more A novel maximum-entropy meshfree method that we recently introduced in Ortiz et al. (2010) [1] is extended to Stokes flow in two dimensions and to three-dimensional incompressible linear elasticity. The numerical procedure is aimed to remedy two outstanding issues in meshfree methods: the development of an optimal and stable formulation for incompressible media, and an accurate cell-based numerical integration scheme to compute the weak form integrals. On using the incompressibility constraint of the standard u–p formulation, a u-based formulation is devised by nodally averaging the hydrostatic pressure around the nodes. A modified Gauss quadrature scheme is employed, which results in a correction to the stiffness matrix that alleviates integration errors in meshfree methods, and satisfies the patch test to machine accuracy. The robustness and versatility of the maximum-entropy meshfree method is demonstrated in three-dimensional computations using tetrahedral background meshes for integration. The meshfree formulation delivers optimal rates of convergence in the energy and L2-norms. Inf–sup tests are presented to demonstrate the stability of the maximum-entropy meshfree formulation for incompressible media problems.
Computer Methods in Applied Mechanics and Engineering, 2010
Numerical integration errors and volumetric locking in the near-incompressible limit are two outs... more Numerical integration errors and volumetric locking in the near-incompressible limit are two outstanding issues in Galerkin-based meshfree computations. In this paper, we present a modified Gaussian integration scheme on background cells for meshfree methods that alleviates errors in numerical integration and ensures patch test satisfaction to machine precision. Secondly, a locking-free small-strain elasticity formulation for meshfree methods is proposed, which draws on developments in assumed strain methods and nodal integration techniques. In this study, maximum-entropy basis functions are used; however, the generality of our approach permits the use of any meshfree approximation. Various benchmark problems in two-dimensional compressible and near-incompressible small strain elasticity are presented to demonstrate the accuracy and optimal convergence in the energy norm of the maximum-entropy meshfree formulation.
International Journal of Computer Integrated Manufacturing, 2009
In the recent years, inter-organisational cooperation has been one of the organisational strategi... more In the recent years, inter-organisational cooperation has been one of the organisational strategies most used to compete and become adapted to the exigencies of the global market. In this context, internal business processes of the cooperative enterprises should interact to pursue common objectives that will be profitable for all parts. Therefore, it is necessary to measure the performance of these business processes under a strategic approach and in a twofold manner, from a global perspective (inter-enterprise) and from an individual or partial perspective (intra-enterprise). Performance measurement systems (PMSs) described in the literature that discuss this context are very different in their conception and broadness. This paper describes the basic characteristics that PMSs should fulfil to cover interoperability requirements and a literature review of the PMSs that deal with business process interoperability in order to gain detailed insight into PMS definition for these contexts. From the literature review, a comparison of the PMSs is obtained with regard to eight core characteristics for these contexts: business process representation, business process measurement, business process lifecycle management, PMS intra and interorganisational levels measurement, process-decomposition approach, intra-inter-process connection measurement, interorganisational coordination measurement, and common interorganisational strategy.
All companies need to know at what level and to what extent they are complying with their objecti... more All companies need to know at what level and to what extent they are complying with their objectives. We present a system called PMS-BP (performance measurement system for business processes) which has been designed to define indicators and evaluate company ...
International Journal of Production Economics, 2009
In recent years, the creation of supply chains (SCs) and selling networks (SNs) has offered firms... more In recent years, the creation of supply chains (SCs) and selling networks (SNs) has offered firms new business opportunities based on collaboration and cooperation. One of these opportunities consists in a better response to dynamic market needs by marketing products/services packages (PS-Ps) with greater added value for the client. The aim of this work is to define a conceptual framework to support the characterization, design, and/or management of one of the key processes in client satisfaction and operational efficiency: the order promising process (OPP) in the context of collaborative selling network (CSN), which markets PS-Ps. To attain this objective, a research method based initially on the search for studies was followed to help define a conceptual framework for OPP characterization, and also the elements and structure it should have. On the basis of this initial search, a structure for a conceptual framework for the characterization of the OPP is proposed and specific studies that assist in determining and defining the contents of such a conceptual framework are analyzed. With the proposed conceptual framework, the members of a CSN can easily and systematically identify and define all the aspects that influence the OPP in a collaborative context, and may design the process in such a way that client satisfaction and SN efficiency are maximized. Furthermore, the framework structure and contents may be useful to analyze existing literature from a scientific point of view, thus enabling the identification of future lines of research.
This paper presents a solution method that supports the order promising (OP) process of a product... more This paper presents a solution method that supports the order promising (OP) process of a product-pack (P-P) in an extended collaborative selling chain (ECOSELL) domain. A P-P is a group of products with complementary functions that can be jointly commercialised. The flexible dimensions of a P-P order request are the conventional ones (quantity, due date, delivery location and price) plus
Computer Methods in Applied Mechanics and Engineering, 2009
Numerical integration errors and volumetric locking in the near-incompressible limit are two outs... more Numerical integration errors and volumetric locking in the near-incompressible limit are two outstanding issues in Galerkin-based meshfree computations. In this paper, we present a modified Gaussian integration scheme on background cells for meshfree methods that alleviates errors in numerical integration and ensures patch test satisfaction to machine precision. Secondly, a lockingfree small-strain elasticity formulation for meshfree methods is proposed, which draws on developments in assumed strain methods and nodal integration techniques. In this study, maximum-entropy basis functions are used; however, the generality of our approach permits the use of any meshfree approximation. Various benchmark problems in two-dimensional compressible and near-incompressible small strain elasticity are presented to demonstrate the accuracy and optimal convergence in the energy norm of the maximumentropy meshfree formulation.
A novel maximum-entropy meshfree method that we recently introduced in Ortiz et al. (2010) [1] is... more A novel maximum-entropy meshfree method that we recently introduced in Ortiz et al. (2010) [1] is extended to Stokes flow in two dimensions and to three-dimensional incompressible linear elasticity. The numerical procedure is aimed to remedy two outstanding issues in meshfree methods: the development of an optimal and stable formulation for incompressible media, and an accurate cell-based numerical integration scheme to compute the weak form integrals. On using the incompressibility constraint of the standard u–p formulation, a u-based formulation is devised by nodally averaging the hydrostatic pressure around the nodes. A modified Gauss quadrature scheme is employed, which results in a correction to the stiffness matrix that alleviates integration errors in meshfree methods, and satisfies the patch test to machine accuracy. The robustness and versatility of the maximum-entropy meshfree method is demonstrated in three-dimensional computations using tetrahedral background meshes for integration. The meshfree formulation delivers optimal rates of convergence in the energy and L2-norms. Inf–sup tests are presented to demonstrate the stability of the maximum-entropy meshfree formulation for incompressible media problems.
Computer Methods in Applied Mechanics and Engineering, 2010
Numerical integration errors and volumetric locking in the near-incompressible limit are two outs... more Numerical integration errors and volumetric locking in the near-incompressible limit are two outstanding issues in Galerkin-based meshfree computations. In this paper, we present a modified Gaussian integration scheme on background cells for meshfree methods that alleviates errors in numerical integration and ensures patch test satisfaction to machine precision. Secondly, a locking-free small-strain elasticity formulation for meshfree methods is proposed, which draws on developments in assumed strain methods and nodal integration techniques. In this study, maximum-entropy basis functions are used; however, the generality of our approach permits the use of any meshfree approximation. Various benchmark problems in two-dimensional compressible and near-incompressible small strain elasticity are presented to demonstrate the accuracy and optimal convergence in the energy norm of the maximum-entropy meshfree formulation.
International Journal of Computer Integrated Manufacturing, 2009
In the recent years, inter-organisational cooperation has been one of the organisational strategi... more In the recent years, inter-organisational cooperation has been one of the organisational strategies most used to compete and become adapted to the exigencies of the global market. In this context, internal business processes of the cooperative enterprises should interact to pursue common objectives that will be profitable for all parts. Therefore, it is necessary to measure the performance of these business processes under a strategic approach and in a twofold manner, from a global perspective (inter-enterprise) and from an individual or partial perspective (intra-enterprise). Performance measurement systems (PMSs) described in the literature that discuss this context are very different in their conception and broadness. This paper describes the basic characteristics that PMSs should fulfil to cover interoperability requirements and a literature review of the PMSs that deal with business process interoperability in order to gain detailed insight into PMS definition for these contexts. From the literature review, a comparison of the PMSs is obtained with regard to eight core characteristics for these contexts: business process representation, business process measurement, business process lifecycle management, PMS intra and interorganisational levels measurement, process-decomposition approach, intra-inter-process connection measurement, interorganisational coordination measurement, and common interorganisational strategy.
All companies need to know at what level and to what extent they are complying with their objecti... more All companies need to know at what level and to what extent they are complying with their objectives. We present a system called PMS-BP (performance measurement system for business processes) which has been designed to define indicators and evaluate company ...
International Journal of Production Economics, 2009
In recent years, the creation of supply chains (SCs) and selling networks (SNs) has offered firms... more In recent years, the creation of supply chains (SCs) and selling networks (SNs) has offered firms new business opportunities based on collaboration and cooperation. One of these opportunities consists in a better response to dynamic market needs by marketing products/services packages (PS-Ps) with greater added value for the client. The aim of this work is to define a conceptual framework to support the characterization, design, and/or management of one of the key processes in client satisfaction and operational efficiency: the order promising process (OPP) in the context of collaborative selling network (CSN), which markets PS-Ps. To attain this objective, a research method based initially on the search for studies was followed to help define a conceptual framework for OPP characterization, and also the elements and structure it should have. On the basis of this initial search, a structure for a conceptual framework for the characterization of the OPP is proposed and specific studies that assist in determining and defining the contents of such a conceptual framework are analyzed. With the proposed conceptual framework, the members of a CSN can easily and systematically identify and define all the aspects that influence the OPP in a collaborative context, and may design the process in such a way that client satisfaction and SN efficiency are maximized. Furthermore, the framework structure and contents may be useful to analyze existing literature from a scientific point of view, thus enabling the identification of future lines of research.
This paper presents a solution method that supports the order promising (OP) process of a product... more This paper presents a solution method that supports the order promising (OP) process of a product-pack (P-P) in an extended collaborative selling chain (ECOSELL) domain. A P-P is a group of products with complementary functions that can be jointly commercialised. The flexible dimensions of a P-P order request are the conventional ones (quantity, due date, delivery location and price) plus
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Papers by Ariel Ortiz