Showing papers on "Verification and validation of computer simulation models published in 1979"

Validation of simulation models

Abstract: This is a tutorial paper on validation of simulation models. Included in this tutorial are what is meant by validation, the problem dependent characteristics of simulation model validation, descriptions of the various validation techniques and their use and a discussion on the statistics used in validation techniques (but not the detailed statistical tests themselves).

The application of program verification techniques to hardware verification

Abstract: The growing complexity of machine designs and costs of engineering changes are increasing the demand for tools and methods to detect errors earlier in the hardware development cycle. Because of similar concerns in the development of software there has been a great deal of work on methods for proving that a program satisfies a given specification. This paper examines one such program verification technique, based on the notion of symbolic execution, and then explores its application to the problem of establishing the correct behavior of a piece of hardware.

Validation of Software Reliability Models

Abstract: : This report presents the results of a study and investigation of software reliability models. In particular, the purpose was to investigate the statistical properties of selected software reliability models, including the statistical properties of the parameter estimates, and to investigate the goodness of fit of the models to actual software error data. The results indicate that the models fit poorly, generally due to in most part the vagaries of the data rather than shortcomings of the models.

Corporate simulation models

Abstract: Publisher Summary The most important factor that differentiates corporate simulation models from other types of simulation models is the fact that corporate simulation models have found their way into the executive suites of some of the largest corporations in the world. There appear to be at least three reasons why risk analysis is not widely used with corporate simulation models. First, the computer run costs are often prohibitively expensive. Second, there are serious problems of validation, experimental design, and data analysis associated with stochastic simulation experiments. Third, risk analysis seems to have only limited appeal to senior corporate executives. The technical problems include (1) the interface between optimization models and simulation models, (2) risk analysis, (3) production planning models, and (4) computer software. The nontechnical problems are (1) ill-defined problem definition, (2) failure to integrate the model into the planning process, and (3) the politics of corporate modeling.

Validation of Simulation Models, I. An Overview and Survey of Real-World Practice.

Abstract: : The problem of assessing the degree to which a model constructed for use in a simulation study faithfully represents the corresponding real system is considered. The focus here is to survey general approaches and methods which have been used in practice, or could be implemented, including good programming techniques, verifying that the program itself is correct, overall goals of the validation of a model, and a general framework for the total validation effort. Several concrete examples are discussed to illustrate the methods as well as possible pitfalls. (Author)

Computer Programs for simulation of logical models

Abstract: Systems involving a small number of variables have been analyzed in the preceeding chapters.

Validating a bus operations simulation model

Abstract: An existing but unvalidated digital simulation model of a system of urban bus routes is reviewed. A data collection project is described which was to yield sufficient field data to allow at least partial validation of the model. Data collection and analysis were completed, although with some difficulty. Previous field results were reviewed and found to be reasonably consistent. High levels of variance were observed so that model inputs derived by averaging, were very approximate. A theoretical fault in the model was also found. Partial validation was attempted, but with limited success. The project provided insights on the model, the problem of bus scheduling, and on the methodology of simulation validation.

Validation and verification of rail-vehicle models

Abstract: A conceptual approach to model validation and verification is developed for application to rail-vehicle systems. In this paper, validation and verification are distinguished, respectively, by association with the qualitative (structure definition) and quantitative (parameter estimation) aspects of the modeling problem. Verifiability is quantitatively described in terms of: (1) the correspondence between the measurable behaviour of a physical system and the model parameters being evaluated, (2) the quantity of measured data available, and (3) the quality of those data. The three factors are directly related to corresponding mathematical terms in a general numerical algorithm for Bayesian statistical parameter estimation. The framework of analysis developed around this concept provides insight to validation test planning, and the establishment of realistic standards or criteria of acceptability for a mathematical model. Examples based on recent experience involving the analysis of a 100-ton hopper car are included in the paper.

Model estimation and verification — Some recent approaches

Abstract: In this paper, data analysis methodologies and procedures are applied to economic data. The appropriateness of this approach to model development and verification is also addressed. Models and data addressing United States housing purchases between the years 1948–1975 are used as a case study. The data and several candidate models of relationships are explicitly examined. Residuals, as well as the data matrix of the independent variables, are examined in some detail.

A human simulation validation of a telephone loop network simulation model

Abstract: A computer simulation model was built to study various strategies for the assignment of telephone loop network facilities to customers. Results of this analysis are presented along with a novel approach to validate the analysis - simulating the simulation model with real data and real assignment personnel.

Time response simulation of the guidance and control system of an automatically steered wire-following vehicle

Abstract: Time-response simulation studies carried out in support of the development and validation of the guidance/steering subsystem of a wire-following-vehicle (WFV) are described. A lateral guidance system is outlined, field testing and simulation validation are covered, and time response simulation results are discussed.

Development of credible computer system simulation models

Abstract: The Problems encountered during a simulation effort are influenced by the objectives of the simulation. Verification and validation of the simulation model are two such problems which affect the credibility (and usability) of the model.A simulation methodology for Program Design Analysis is described. The goal of this simulation application is to test a design before it is implemented.Techniques are described which enhance the credibility of simulation models. The relationship between Program Design Analysis and the reliability of the system being developed is explored.