Engineering Approaches

Journal of Electronics ManufacturingVol. 01, No. 02, pp. 97-104 (1991) PapersNo AccessThe concurrent engineering approach to product developmentMICHAEL J. O’FLYNN and M. MUNIR AHMADMICHAEL J. O’FLYNNDigital Equipment Corporation, Manufacturing Engineering Department, Ballybrit Industrial Estate, Galway, Ireland Search for more papers by this author and M. MUNIR AHMADDepartment of Mechanical and Production Engineering, University of Limerick, Limerick, Ireland Search for more papers by this author https://doi.org/10.1142/S0960313191000126Cited by:0 Previous AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail AbstractThe manufacturing sector has experienced significant changes over the past twenty years. Companies are becoming more international and are facing increased competitive challenges. Because of this, and owing to higher customer expectations, there are greater demands on product quality, functionality, aesthetics, reliability, and flexibility. In addition, product life-cycles have reduced which has led to shorter time periods in which to recover costs. There is greater pressure on design teams to develop products in shorter time periods as profits have been shown to be very sensitive to time-to-market (TTM). Many of the above factors are directly influenced during product development and therefore the approach adopted during this phase of the product life-cycle can have a major impact on profitability. This paper defines the simultaneous or concurrent engineering (CE) approach to product development, and the benefits of adopting it, versus the traditional sequential engineering approach. CE implementation techniques, including formal methodologies and computer-based initiatives, currently employed or being developed, are described. Finally, an overview of a design for manufacture (DFM) expert model for PWB design and manufacture, based on minimising manufacturing costs, is presented (in this context, a PWB includes printed wiring board plus componentry).Keywords:Concurrent engineeringsimultaneous engineeringdesign for manufactureproduct development FiguresReferencesRelatedDetails Recommended Vol. 01, No. 02 Metrics History KeywordsConcurrent engineeringsimultaneous engineeringdesign for manufactureproduct developmentPDF download

When people are asked to described certain textiles, they frequently refer to the expressions of its properties such as attractiveness, uniqueness, shininess, robustness, comfortability, and so on. It shows how senses play important role in it. Human employs their senses when interacting with textiles, most notably visual and tactile/ haptic to absorb its expressive properties. Yet, our sensorial experiences may amplify when interacting with those of traditional textiles, such as batik, as we can entice sensations when seeing its motifs and patterns, smelling its materials, and touching its surfaces. The multi-sensorial importance of seeing, smelling, and touching in the interaction with and experience of textiles suggests that one should address senses in a systematic way when evaluating users' perception on traditional textiles. To address this issue, the paper proposes the incorporation of Kansei Engineering (KE) approach for identifying multi-sensorial experiences on the expressive properties of traditional textiles, using batik as a case of study. KE approach address person's psychological understanding when observing things in order to analyze and study the inherent relationship between person's perceptual knowledge and objects evaluated. This paper outlines the use of KE approach in correlating sensorial perceptions when experience with traditional textiles and ultimately expose users' preferences toward them. Background of KE approach on textiles will be explored and its application for the multi-sensorial investigation of traditional textiles will be discussed.

ABSTRACTThis paper discusses the design of multi‐usage systems able to perform various missions inside buildings, including inspection, digitization, monitoring of construction work, and evaluation of technical performances of the building. Designing such systems, carrying out various missions in different operational environments, is a complex task and requires adopting a well‐defined engineering approach. A model‐based systems engineering (MBSE) approach is proposed and applied to address the complexity of the indoor multi‐usages system and to lead its development. The proposed method provides several complementary and comprehensive views of the system.

Derivation of the relation called the 'reversal' transformation, joining matrices in the two alignments, is presented. To arrive at the solution, a concept of 'polarization and spatial phase' vectors for antennae and waves, different from complex antenna heights and complex wave amplitudes, has been applied. For Sinclair and Jones matrices, describing the same physical phenomenon of nondepolarizing scattering, two different Poincare/spl acute/ sphere models have been proposed based on decomposition of a Sinclair matrix into two transformations of inversion and rotation of the Poincare sphere of incident polarizations. For the Jones matrix model another Sinclair matrix has been determined followed by an additional orthogonality transformation. Such a difference in construction of the two models can explain diverse physical interpretations of their operation. Limited number of simple formulae describing scattering will be obtained when applying to radar polarimetry a special 'engineering approach' introduced in the paper.

This paper presents an overview of why Model Based System Engineering (MBSE) is the mandatory solution to engineer complex railway systems and subsystems, giving some insights about the complexity and technical challenges. But its main focus will be on how MBSE can be a key enabler on the implementation of an extend enterprise approach in the engineering domain. The case study is on rolling stock systems and brake subsystems developed by the two companies Bombardier Transportation and Knorr-Bremse which are in a customer-supplier relationship.

Fiber-Optics Structural Mechanics deals with the application of methods and approaches of Engineering and Applied Mechanics to the stress/strain analysis, rational physical design and reliability of fiber-optics structures and systems. It considers the specifics, associated with the properties of the materials used, typical structures employed, as well as the nature, magnitude and variability of the applied loads. In the review that follows we examine, using methods and approaches of Engineering and Applied Mechanics, a number of practically important problems of the mechanical behavior and structural (“physical”) design of bare or coated optical fibers, experiencing thermal, mechanical or dynamic loading. The following major topics are addressed: bending of bare silica fibers, fibers under the combined action of bending and tension, large deflections of fibers, effect of material's nonlinearity, mechanical behavior of polymer coated or metallized fibers, elastic stability and low temperature microbending of optical fibers, solder materials and joints employed in fiber optics, and dynamic response of optical fibers to shocks and vibrations. We conclude that the application of the methods and approaches of Fiber Optics Structural Mechanics (Structural Analysis of fiber optics systems) can be very helpful in creating a viable and reliable fiber optics products and networks.

Radiolucent lines on immediate postoperative cemented acetabular component radiographs between the PMMA bone cement mantle and bone are an indicator of an increased risk of early loosening. The cause of these lines has yet to be identified. Thermal and chemical necrosis, fluid interposition and cement shrinkage have all been suggested in the literature. The aim of the study reported here was to take an engineering approach – eliminating confounding variables present during surgery – to quantify the size of the interstice created by cement shrinkage when a 50 mm diameter flanged acetabular cup is implanted in a model acetabulum with a 52 mm hemispherical bore under controlled conditions using vacuum and non-vacuum mixed cement. Irrespective of the mixing method used, a significant interstice was created between the bone cement and the mock acetabulum. When the cement was mixed under vacuum the interstice created between the mock acetabulum and the cement mantle was 0.60 mm ± 0.09 mm; when the cement was mixed under non-vacuum conditions the interstice created was 0.39 mm ± 0.15 mm. Possible explanations for radiolucent lines are discussed.

TN recent years engineering data have been increasingly used in studying the input-output relationship in manufacturing industries. Ideally the fundamental mechanical properties underlying a production process are relied on to answer many questions on input-output relationships. This enables the investigator to exclude such variables as management from a production function, and to isolate the effects of other variables by letting them vary one at a time. In actuality, most of the engineering data are compiled by engineers from their experience with actual practices rather than from carefully conducted experiments. But most of the advantages of the engineering approach remain generally present, and its basic usefulness has been repeatedly asserted.' One of the major road blocks in the engineering approach has been the difficulty of estimating the labor-output relationship. Usually one searches in vain for any labor requirement data in engineering literature; and because of the large variation in the workload among plants, reliance on sample observations is apt to be misleading. More fundamentally, because of the heterogeneity in skill and efficiency the quantity of labor input cannot be measured precisely. It is hardly surprising, therefore, that no serious attention has been given to the laboroutput relationships derived with the engineering approach. In this paper we will attempt to demonstrate some of the merits of a special type of engineering data, based on job analysis, which so far has been almost completely ignored by economists. Compiled mainly by time-and-motion study engineers for such industries as the textile, garment, and machine tool industries, these data give the detailed elements of the jobs in a manufacturing process, and the time required to perform them under specified circumstances. This enables the engineer, as well as the economist, to explain the differences in the performance of individual workers. Ideally the elements of efficiency and skill can be isolated, and it becomes possible for the investigator to study the pure effects of technological change on labor-output relationship, or such problems as substitution between labor and other inputs. The rest of this paper will be divided into five sections. In the first section we will describe a method by which the job analysis data may be used, jointly with other engineering data, in computing historical series of certain input-output relationships. In the next the job analysis data are applied to a problem of substitution between labor and machinery, and the results are shown to have justified, on the whole, the method used in the previous section. Next, labor-output series compiled with two alternative methods are given, to be used in the subsequent section for the demonstration of an important implication in the use of job analysis data. Finally, a brief summary is given.

Shared software in the production environment

Directed evolution: new parts and optimized function

This work is dedicated to the systematic investigation of wind turbine wakes under the effect of pressure gradients. Wind tunnel experiments are carried out with a wind turbine positioned on straight ramps of increasing angle such that it experiences an approximately linear flow speed-up/slow-down from the induction region into the far wake. Fifteen ramp angles are studied: 7 favorable (FPG), 7 adverse (APG), and 1 zero pressure gradient. The wake center is shown to follow the base flow streamline originating from a virtual turbine hub height. A quasi-linear relationship between the pressure gradient and near wake length is demonstrated. Far wake characteristics, such as the recovery of the wake center velocity deficit and wake growth rate, are observed to systematically vary with the pressure gradient. The wake recovery rate increases (decreases) with the increase in the FPG (APG), and the wake growth rate shows a linear increase from most favorable to most adverse pressure gradient. The turbine power coefficient decreases significantly with increasing APG to a greater degree than the increase in power coefficient under FPG. The engineering approach of superposing the wake deficit predicted by the standard Gaussian model on the modified base flow is shown to work for very moderate pressure gradients. In light of this, a threshold in terms of flow speed-up/slow-down along the wake trajectory is established, below which the engineering approach can be reasonably employed. Finally, a physics-based model for wakes under the pressure gradient is tested. A new theoretical relation for near wake length under the pressure gradient is proposed. Using the theoretical near wake length, the pressure gradient model predicts the turbine wakes for all cases with good accuracy and shows a significant improvement from the engineering approach.

This article explores the valuation of natural capital by critically analysing alternative approaches to it. It considers the problems associated with applying economic values to natural capital and the limitations of such exercises. It examines different methods that are more familiar to accountants than economists of using what is sometimes termed ‘an engineering approach’ to estimating the costs of maintaining and restoring existing assets. It considers the arguments that are used to justify the two. In particular, it addresses the question of what we are seeking to do by determining the value of natural capital—what is the question to which valuation is supposed to be the answer?

Research was undertaken with the goal of developing productivity functions that explain the changes in the productivity is Israeli ports by means of changes in various explanatory factors. Productivity is measured by an engineering aproach, i.e. actual performance is measured against engineering standards. Partial productivity indices are worked out for each factor separately and aggregated to yield a total productivity index, which is calculated in two ways: one uses updated standatds as a basis of comparison (giving local productivity) and the second uses comparison standards of a basic period (yielding comparative productivity figures). The paper examines the theories and assumptions within the ports of Israel, which offer a good example for analysing productivity because they are characterized by significant developments in the quality and quantity of inputs. The ports have experienced many technological developments that have had a crucial effect on the nature of their activity. The explanatory factors were examined, out of which were chosen those in each family that corelate best with productivity. A linear programming model is generated for developing productivity functions with an objective function of minimum deviations between calculated and actual productivity. The constranints in this model ensure that the coeficients remain within ranges that are meaningful with regard to the problem uner examination. Productivity measures based on the engineering approach and the productivity functions developed herein can be engineering approach and the productivity functions developed herein can be utilized as aids in managing ports and in determining what steps should be taken to improve productivity.

With the rise of electric and connected vehicles and an increased number of automated functions and sensors, the information shown to the driver changes. This contribution presents an engineering approach for designing and optimizing HMI interfaces to enable the driver to quickly be aware of all relevant information. In a study 6 master students in their final year of an HMI automotive design course either applied the engineering approach or used their preferred mix of methods to design a control panel that considers a pre-defined set of information to support three basic tasks: navigation, comfort and energy status. In a subsequent lab study, 27 students were presented with different situations on the designs. Participants should choose an action appropriate to the situation as soon as possible. The response time for the designs created with the engineering approach was 387 ms faster (p=0.015).

Buckling strength is very important parameter for the compression load crying capacity of the hydraulic cylinders. The complexity of the determination of this parameter appears if the assembly of the hydraulic cylinder is detailed taking in to account: the cylinder, the piston rod, the joint between these parts and the pressure in the cylinder. The aim of the presented research is to evaluate some simplified engineering approaches used in the industrial design of the hydraulic cylinders and to suggest a suitable models applicable to use with the CAE software.DOI: http://dx.doi.org/10.5755/j01.mech.22.6.15374