Structured approach to the design of a production data analysis facility Part 2: Implementation and evaluation

This paper reports research into a novel machining, inspection and analysis facility directed towards a small manufacturing enterprise. A major feature of the facility is the ability to produce rapid manufacturing control through feedback data generated from the seamless integration of machining, inspection and production data analysis activities in order to influence the regeneration of NC part programs. The major contribution of the paper explores the implementation and evaluation of a prototype production data analysis facility that consists of four constituents: machine and inspection planning, production code generation, comparative tolerance analysis, and manufacturing data analysis, the execution of which is supported by the use of order and manufacturing information models. An integrated multifunctional prototype production data analysis software tool has been developed for a limited number of manufacturing features for 2½D prismatic components. This prototype software tool has been tested and is critically reviewed with future work.     

Conceptual design of industrial systems: an approach to support collaboration

The design of any industrial system is a complex problem where many domains are involved. Each domain developed its own way of modeling based on a mono disciplinary perception. This leads to a communication problem and consequently to expectations on the formulated solution that do not correspond with the real solution. To enable the communication between domains and to preserve the match between intentions, expectations and reality of the system to be designed, a combination of a soft and hard systems approach is used to define a Conceptual model for Industrial Systems (CIS). The use of the model during design is illustrated for the technical domain, but has proven to be applicable for the organization and information domain as well.     

Metrological approach to design and production

One of the requirements presented to designs is that the geometric parameters must be inherently measurable. From the metrological position, the conventional terminology and treatment of this subject hide the fact that nonmeasurability of parameters for a design is equivalent to indeterminacy or inoperability. The “metrological” approach, together with the inadequacies of the language used to describe designs, provides the author with a basic source of design errors and serious obstacles to automation of this sphere of industrial activity. Translated from Izmeritel'naya Tekhnika, No. 4, pp. 17–22, April, 1998.     

Conceptual approach to introduction of information technology into the field of simulation

We consider results of research by the faculty for design and production of radio equipment at Penza State University; the research was concerned with development of methods, models, algorithms, and software packages for investigating complex mechanical systems, technologies, and simulation of physical processes. Translated from Izmeritel'naya Tekhnika, No. 5, pp. 7–11, May, 1999.     

Fuzzy approach to the robust facility layout in uncertain production environments

The proposed method approaches the problem of the optimal facility layout using fuzzy theory. The optimal layout is a robust layout that minimizes the total material handling cost, when the product market demands are uncertain variables, which are defined as fuzzy numbers. Since each department has a limited production capacity, not all possible combinations, deriving from each product's market demand, are taken into account because some combination could exceed the overall department's productivity. Therefore, the optimal solution results by solving a 'constrained' fuzzy optimization problem, in which the fuzzy material handling costs corresponding to the layouts are evaluated, and a ranking method, which considers the grade of pessimism of the decision maker, is established to determine the optimal layout.     

Product platform design through clustering analysis and information theoretical approach

An effectively designed product platform is vital to the final product family derived from it. A product platform design consists of platform configuration to decide which variables to make common across the product family and to determining the optimal values for platform and scaling variables for all product variants. Many existing product family design methods assume a given platform configuration, i.e. the platform variables are specified a priori by designers. However, selecting the right combination of common and scaling variables is not trivial. Most approaches are single-platform methods, in which design variables are either shared across all product variants or not at all. While in multiple-platform design, platform variables can have special value with regard to a subset of product variants within the product family, offering opportunities for superior overall design. This paper proposes a quantitative method for scale-based multiple-platform design using clustering analysis and Shannon's Entropy theory. Optimization methods are used to design the product family by holding the values of platform variables constant and to find the best values of the scaling variables. An information theoretical approach is used to help select platform variables based on the clustering analysis of individually designed products. Validity analysis is performed to determine the optimal settings for platform variables. Local clustering is further performed on each platform variable, to establish subsets of variants such that variants within a subset are more similar to each other than they are to variants in other subsets and a common value is used to represent the various values of variants in each subset. A case study is used to illustrate the process of the proposed method, and the design solutions are compared with that found by other methods given in previous literature. The comparison results verified that the multiple-platform design can lead to superior solutions of product family.     

Approach to the design and data analysis of a limb-scanning experiment

The design of spectroscopic measurements of the atmosphere with the limb-scanning technique for the retrieval of constituent altitude profiles requires choosing instrumental, observational, and retrieval parameters. An approach to this problem is discussed, and the mathematical tools that make it possible to study the trade-off between the two conflicting requirements of optimum vertical resolution and small error of the profile are derived. As a first illustrative application, implementation of the mathematical tools in the design of measurements to be carried out from a satellite platform is shown; a set of parameters that provide a satisfactory compromise between the vertical resolution and the uncertainties of the retrieved profile has been identified. The mathematical model discussed can simulate the results obtained with retrieval techniques that are based on the global inversion of the kernel that relates the observations and the unknown profile. As a second application, a comparison between the a priori estimate of the uncertainties provided by the mathematical tools and the results of the global analysis of data collected with a balloon-borne experiment is shown.     

From user requirements to commonality specifications: an integrated approach to product family design

Many companies design families of products based on product platforms that enable economies of scale and scope while satisfying a variety of market applications. Product family design is a difficult and challenging task, and a variety of methods and tools have been created to support this platform-based product development. Unfortunately, many of these methods and tools have been developed—and consequently exist—in isolation from one other. In this paper, we introduce an approach to integrate several of these disparate tools into a framework to translate user needs and requirements into commonality specifications during product family design. The novelty of the approach lies in how we integrate the market segmentation grid, Generational Variety Index (GVI), Design Structure Matrix (DSM), commonality indices, mathematical modeling and optimization, and multi-dimensional data visualization tools to identify what to make common, what to make unique, and what parameter settings are best for each component and/or subsystem in the product family. The design of a family of unmanned ground vehicles (UGVs) demonstrates the proposed approach and highlights its benefits and limitations.     

Strategic management/design approach to a job-shop production system

A macro-level (or economic) model of a job-shop is proposed and developed for periodic and dynamic types. A strategic management/design approach is discussed by applying the two-stage design method. It gives the problem of setting the economic leadtime in the respective models. The existence of economic leadtime is ascertained numerically, and a design comparison of a periodic versus a semidynamic type is given. The pair-matrix table consisting of economics and reliability elements is then given for summary, and a strategy for demand-to-supply management is discussed on ellipse shape. Finally, an real situation is introduced and the validity of modelling shown.     

An approach to the design of production systems giving a high quality of working life and production efficiency

People's social and economic desires are gradually becoming more versatile and fragmented. Industries should be developed in such a way that these versatile human desires are brought into harmony with the organizational needs of production engineering.

In this paper we report on the state of the desires and motivations of Japanese workers in 1974 and 1977 resulting from investigation and analysis using application methods of multivariate analysis and give an example of new production systems in which workers are in harmony with organizational needs.     

Optimal design of stochastic production lines: a dynamic programming approach

We consider the problem of choosing the number and type of machines for each station in a new production line where the sequence of processes (i.e., manufacturing recipe) has already been established. We formulate a model to minimize cost (investment plus operating) subject to constraints on throughput and cycle time. Using queueing network approximations within a dynamic programming framework, we develop a line design algorithm that works in station-wise fashion. For computational tractability, we must discretize a continuous state space. However, we are able to compute bounds on the error in the cost function as a guide to the appropriate choice of grid size. We conclude by applying our algorithm to an industrial problem that motivated this work.     

A simplified approach to the damage tolerance design of asymmetric tapered laminates. Part II: Methodology validation

An analytical approach for the computation of the energy release rates associated with ply drop-offs has been presented in Part I of this study; the methodology is based on the Euler–Bernoulli theory applied to layered beams, together with orthotropic rescaling. The analytical approach accounts for both thick and thin section delaminations, as well as for variable tapering angles. This paper presents the validation for the analytical methodology which has been developed in Part I. The validation is carried out via: (1) comparison with finite element solutions in terms of energy release rates versus delamination length; (2) prediction of delamination onset load in experimentally characterized tapered samples under combined tension and bending.     

A simplified approach to the damage tolerance design of asymmetric tapered laminates. Part I: Methodology development

Tapered composite laminates are susceptible to interlaminar damage in the form of delaminations growing from ply drop-off locations. This study presents an analytical method for the calculation of the energy release rates associated with interlaminar cracks emanating from the ply termination in both the laminate thick and thin sections, also accounting for the effects of the tapering angle. The proposed approach is based on modeling asymmetrically tapered composite laminates as assemblies of layered Euler–Bernoulli beam segments; these are split and reconnected through-the-thickness at the ply-drop-off location. The presence of a local resin pocket is explicitly considered in the model. Orthotropic rescaling is employed in order to take into account the material behavior through-the-thickness. This paper presents the analytical formulation of the proposed approach, whose validation follows in part II.     

Hybrids-a review: Part 1. Techniques,design and construction

A continuation of the previous review on carbon fibre and glass fibre hybrid reinforced plastics (cghrp) is presented. The first section covers fabrication techniques, design, cost-effectiveness and applications. The second section, to be published in the next issue, covers the thermal and mechanical properties of cghrp.     

Conceptual design optimization of rectilinear building frames: A knapsack problem approach

This article presents an automated technique for preliminary layout (conceptual design) optimization of rectilinear, orthogonal building frames in which the shape of the building plan, the number of bays and the size of unsupported spans are variables. It adopts the knapsack problem as the applied combinatorial optimization problem, and describes how the conceptual design optimization problem can be generally modelled as the unbounded multi-constraint multiple knapsack problem. It discusses some special cases, which can be modelled more efficiently as the single knapsack problem, the multiple-choice knapsack problem or the multiple knapsack problem. A knapsack contains sub-rectangles that define the floor plan and the location of columns. Particular conditions or preferences for the conceptual design can be incorporated as constraints on the knapsacks and/or sub-rectangles. A bi-objective knapsack problem is defined with the aim of obtaining a conceptual design having minimum cost and maximum plan regularity (minimum structural eccentricity). A multi-objective ant colony algorithm is formulated to solve the combinatorial optimization problem. A numerical example is included to demonstrate the application of the present method and the robustness of the algorithm.     

An approach to functional synthesis of solutions in mechanical conceptual design. Part III: Spatial configuration

These three papers describe an approach to the synthesis of solutions to a class of mechanical design problems; these involve transmission and transformation of mechanical forces and motion, and can be described by a set of inputs and outputs. The approach involves(1) identifying a set of primary functional elements and rules of combining them, and(2) developing appropriate representations and reasoning procedures for synthesizing solution concepts using these elements and their combination rules; these synthesis procedures can produce an exhaustive set of solution concepts, in terms of their topological as well as spatial configurations, to a given design problem.This paper (Part III) describes a constraint propagation procedure which, using a knowledge base of spatial information about a set of primary functional elements, can produce possible spatial configurations of solution concepts generated in Part II.     

A study on bullock carts. Part 1. Engineering analysis of the two-wheel bullock cart design

An engineering analysis of the design of two-wheel bullock carts has been carried out with the aid of a mathematical model. Non-dimensional expressions for the pull and the neck load have been developed. In the first instance, the cart is assumed to be cruising at constant velocity on a terrain with the effective coefficient of rolling friction varying over a wide range (0.001 to 0.5) and the gradient varying between +0.2 to −0.2. Subsequently, the effect of inertia force due to an acceleration parallel to the ground is studied. In the light of this analysis, two modifications to the design of the cart have been proposed and the relative merits of the current designs and the proposed designs are discussed.