scholarly journals Design margins: a hidden issue in industry

2019 ◽  
Vol 5 ◽  
Author(s):  
Claudia Eckert ◽  
Ola Isaksson ◽  
Chris Earl
Keyword(s):  
Critical Role ◽  
Design Solution ◽  
Clear Understanding ◽  
Design Decisions ◽  
Engineering Change ◽  
Jet Engine ◽  
Complex Products ◽  
Design Alternatives ◽  
Engine Component ◽  
A Company

In complex products the values of parameters are rarely exactly the required values, rather they often have a margin that might be designed in deliberately or be the incidental results of other design decisions. These margins play a critical role in design processes in managing engineering change and iteration. While engineers often talk about margins informally, designers and researchers also use other terms for specific margin concepts. This paper reviews the existing literature on related concepts and defines margins formally. It discusses the role margins play in handling uncertainty by distinguishing between buffer and excess. Buffer deals with uncertainty and excess with the remaining overcapacity of the design. Buffer can transition into excess of the design solution if the uncertainty can be reduced. The concepts are applied to the temperature margins of several candidate materials for a non-rotary jet engine component. This shows that a clear understanding of margins can help a company to select design alternatives.

scholarly journals Designing as playing games of make-believe

2020 ◽  
Vol 6 ◽  
Author(s):  
Michael Poznic ◽  
Martin Stacey ◽  
Rafaela Hillerbrand ◽  
Claudia Eckert
Keyword(s):  
Design Teams ◽  
Jet Engine ◽  
Complex Products ◽  
Component Design ◽  
External Stakeholders ◽  
Engine Component ◽  
Design Activities ◽  
Held Back

Designing complex products involves working with uncertainties as the product, the requirements and the environment in which it is used co-evolve, and designers and external stakeholders make decisions that affect the evolving design. Rather than being held back by uncertainty, designers work, cooperate and communicate with each other notwithstanding these uncertainties by making assumptions to carry out their own tasks. To explain this, the paper proposes an adaptation of Kendall Walton’s make-believe theory to conceptualise designing as playing games of make-believe by inferring what is required and imagining what is possible given the current set of assumptions and decisions, while knowing these are subject to change. What one is allowed and encouraged to imagine, conclude or propose is governed by socially agreed rules and constraints. The paper uses jet engine component design as an example to illustrate how different design teams make assumptions at the beginning of design activities and negotiate what can and cannot be done with the design. This often involves iteration – repeating activities under revised sets of assumptions. As assumptions are collectively revised, they become part of a new game of make-believe in the sense that there is social agreement that the decisions constitute part of the constraints that govern what can legitimately be inferred about the design or added to it.

scholarly journals Risk Profiles Along the Lifecycle in Dynamic Markets

2015 ◽  
Vol 6 (3) ◽  
pp. 35-46
Author(s):  
Tamas Koplyay ◽  
Brian Mitchell ◽  
Sorin Cohn ◽  
Maria Fekete ◽  
Abdelkader Jazouli
Keyword(s):  
Value Chain ◽  
Critical Role ◽  
Distribution Channel ◽  
Operating Mode ◽  
Life And Death ◽  
Dynamic Markets ◽  
Start Up ◽  
Distribution Channel Management ◽  
A Company

Abstract That supply chain management and logistics are a determining factor for the long term success of a company was well documented by Forrester over a half century ago [1], with the importance of the statement only growing through the intervening years.Whether consciously factored into the operating mode or not, logistics and distribution channel management plays a critical role in the life, and death, of a firm. From the rudimentary beginnings of the start-up company to the hectic world of the growth company and onto the relatively secure existence in mature markets, the value chain consisting of logistics and distribution channel linkages follows the firm, until it solidifies into immutable form of the mature value chain and begins to exert an inexorable pressure on the survival of the entire chain, and conversely the chain imposes its will on the members. The emergence of mature industry value chains is often driven by the need to monopolistically control logistics and distribution channels which provides a competitive advantage but also introduces a serious exposure to pending shock loadings of the chain.

scholarly journals Mechanisms and Dynamics in the Interplay of Trust and Distrust: Insights from Project-based Collaboration

2021 ◽  
pp. 017084062110402
Author(s):  
Angelos Kostis ◽  
Maria Bengtsson ◽  
Malin Harryson Näsholm
Keyword(s):  
Critical Role ◽  
Negative Effects ◽  
Interorganizational Trust ◽  
Complex Products ◽  
Conceptual Distinction ◽  
Interorganizational Projects ◽  
Complex Solutions ◽  
Behavioral Mechanisms ◽  
Organizing Principles

Trust and distrust are two distinct organizing principles that play a critical role in interorganizational projects where highly interdependent organizations collaborate to build tailor-made and technologically-complex solutions. Whereas an emerging body of research has debated the conceptual distinction between trust and distrust, this paper emphasizes the processual nature of trusting and distrusting and the interplay between them. Drawing upon insights from project-based collaboration in a complex products and systems (CoPS) industry, we explore the distinct cognitive and behavioral mechanisms through which trust and distrust work, and orient firms towards optimism and watchfulness in the interaction. Our findings show that trust and distrust can act both as substitutes and complements through three interconnected dynamics—undermining, enabling and compensating. These dynamics develop and recursively interrelate through interfirm interactions within single projects and in the broader network. We conclude by presenting our contributions to interorganizational trust literature and by proposing that the interplay of trust and distrust can have both positive and negative effects on the pursuit of project-based relationships.

Towards a Rational, Narrative-Based Design Framework for Navigating Radical Uncertainty in Engineering Design

2021 ◽  
Author(s):  
Kenneth M. Bryden ◽  
Scott Ferguson
Keyword(s):  
Decision Making ◽  
Engineering Design ◽  
Critical Role ◽  
Social Enterprises ◽  
Design Framework ◽  
Design Alternatives ◽  
Human Decision ◽  
Practical Engineering ◽  
Radical Uncertainty ◽  
High Level

Abstract This paper examines decision making under radical uncertainty in engineering design, that is, engineering decision making in those situations where it is not possible to know the outcomes and/or construct the utility functions and probabilities needed to support rational-human decision making. In these situations, despite being faced with radical uncertainty, engineers do (and must) proceed forward in a linear, clear, and predictable manner. Yet, they may not proceed in a manner that is well described by current engineering design frameworks. Examining the role of decision making in business and other social enterprises, Tuckett and Nikolic [1] have proposed conviction narrative theory (CNT) to describe how rational decision-makers confronted with situations in which insufficient information is available to support traditional decision-making tools use narrative and intuition to reach convincing and actionable decisions. This paper proposes that, in a manner similar to what is described in CNT, narrative and engineering judgment play a critical role in engineering design situations dominated by radical uncertainty. To that end, this paper integrates the traditional rational-human view of decision making as expressed by Hazelrigg in the well-known Decision-Based Design (DBD) framework and CNT as proposed by Tuckett and Nikolic. In the resulting rational, narrative-based design framework, narrative structures are used to describe and develop design alternatives and provide the ideas, beliefs, and preferences needed by the DBD framework. The resulting preferred design is expressed as a narrative and tested using engineering judgement. Specifically, the goal of the design process is expressed as a high-level guiding narrative that fosters the development of design narratives (design alternatives), and ultimately results in a convincing narrative that describes the preferred design. The high-level guiding narrative outlines the event(s), entity(s), preferences, and beliefs needed to support the design. The design narratives are narrative fragments that are nested within the high-level narrative and include the proposed action (idea), the specific challenges that the design faces, and the possible (but not yet verified) outcomes. The convincing narrative is the validated, preferred option that results from the DBD analysis and optimization process and is reviewed using engineering judgement. Following development of the rational, narrative-based design framework, the value of the framework is discussed within the context of practical engineering design.

Abstract P258: Factors Associated With Imaging Choice of Acute Ischemic Stroke Patients and the Related Health Outcomes

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Jason J Wang ◽  
Artem Boltyenkov ◽  
Gabriela Martinez ◽  
Jeffrey M Katz ◽  
Angela Hoang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Health Outcomes ◽  
Acute Ischemic Stroke ◽  
Regression Models ◽  
Critical Role ◽  
Clear Understanding ◽  
Negatively Associated ◽  
Factors Associated ◽  
To Receive ◽  
Iv Tpa

Introduction: Acute ischemic stroke (AIS) presents an ongoing challenge for population health and availability of healthcare resources. Imaging plays a critical role in both diagnosis and treatment decisions in AIS, but optimal utilization regarding advanced imaging with angiography and perfusion using either CTAP or MRAP remain uncertain according to national guidelines. Consequently, wide variation in AIS imaging exists in clinical practice, mostly defaulted to physician preferences and institutional factors, without a clear understanding of the benefits and risks involved in stroke care. Although CTAP and MRAP each have unique benefits and risks in the AIS setting, the effect of this risk-benefit tradeoff on health outcomes and utilization of resources is unknown. This study analyses the factors associated with imaging preferences and the related health outcomes. Method: We performed a retrospective study on an AIS registry consisting of consecutive patients admitted to our institution from November 1, 2011, through October 1, 2018. Imaging and treatment selections and modified Rankin Score (mRS) at discharge were the main outcomes. Independent variables include age, gender, race-ethnicity, and NIH stroke score (NIHSS) at admission. Multivariable logistic regression models were performed. P<0.05 was considered statistically significant. Results: 1884 patients with curated imaging data during hospitalization were included. Among them, 32% were ≥80 years old, 47.4% female, 15.53% black, 60.3% white, and 24.4% with NIHSS≥10 at admission. CTAP and MRAP were performed in 21.1% and 72.2% patients, respectively. 46.1% received thrombolytics (IV-tPA), 1.3% had endovascular therapy (EVT), and 52.7% were not treated. The two clinical outcomes were independent functionality at discharge (mRS0-2) at 48.4%, and patients expired in hospital at 7.1%. Adjusted by all the factors, regression models showed that patients with NIHSS≥10 were more likely to receive CTAP (p<0.0001, OR=3.39) and less likely to receive MRAP (p<0.0001, OR=0.48); whereas age ≥80 was less likely to receive CTAP (p<0.0001, OR=0.37) or MRAP (p<0.0001, OR=0.37). NIHSS≥10 (p<0.0001, OR=0.15) and IV-tPA (p=0.0006, OR=0.69) were negatively related to independent functionality at discharge, and MRAP (p<0.0001, OR=1.97) was positively related to it. NIHSS≥10 (p=0.0212, OR=1.69) were positively related to mortality, while utilization of MRAP showed a negative relationship (p<0.0001, OR=0.26) with it. Conclusion: Higher NIHSS was positively associated with mortality and utilization of CTAP, while it is negatively associated with MRAP. MRAP was positively related to independent functionality at discharge. Older age was negatively associated with CTAP or MRAP utilization.

scholarly journals Gears Galore!

2013 ◽  
Vol 135 (04) ◽  
pp. 51-54 ◽  
Author(s):  
Lee S. Langston
Keyword(s):  
Fuel Consumption ◽  
Gas Turbines ◽  
Historical Analysis ◽  
Jet Engines ◽  
Efficient Operation ◽  
Jet Engine ◽  
The Status ◽  
The 1960S ◽  
A Company ◽  
Bypass Ratio

This paper presents a review of gas turbines and Honeywell, a company based in Phoenix, history. The article through the review and historical analysis intends to provide perspective on the status of geared fan engines. The addition of a fan to a jet engine, first proposed by Frank Whittle, one of the inventors of the jet engine, increases thrust and reduces fuel consumption. Pratt & Whitney and Rolls Royce were the first to develop a dual spool engine for more efficient operation over a range of flight conditions. Work started on the geared fan TFE731 at the Garrett AiResearch Phoenix Division in 1968. The TFE731 gearbox resulted in a gear reduction of 1.8:1, to power the fan for a 2.5 bypass ratio, which was very high for the 1960s. Honeywell also has another geared turbofan engine, the ALF502. It was developed by AVCO Lycoming in Stratford, Connecticut, and has a 6000–7000 lbt thrust range. Honeywell’s successful 45-year record of producing geared fan small gas turbines gives promise of a bright future for geared fans on large commercial jet engines, providing lower fuel consumption and less noise.

Health Promotion Evaluation and Research in Schools: Issues for Consideration

1999 ◽  
Vol 5 (4) ◽  
pp. 37 ◽  
Author(s):  
Nyanda McBride
Keyword(s):  
Health Promotion ◽  
Program Implementation ◽  
School Health ◽  
Health Program ◽  
Critical Role ◽  
School Setting ◽  
Clear Understanding ◽  
School Settings ◽  
Planning Approach ◽  
Practical Implications

Schools offer an attractive means for health promotion practitioners interested in improving the health of young people and therefore schools play a critical role as a setting for health promotion and public health program implementation. As a consequence schools are also settings in which evaluation and research is undertaken. This paper will discuss some broad issues that the literature suggests are important considerations for evaluation and research undertaken in school settings and discusses some of the practical implications of these considerations. Evaluation of school health promotion requires a balance between systematic, regulated research design and the variable, uncontrolled environment inherent in naturalistic settings. A clear understanding about the nature of the school setting, coupled with an evaluation targeted at the appropriate research phase and incorporating lessons learnt from previous interventions are various issues that need to be considered in well planned evaluations. A planning approach that takes into consideration the evaluation issues raised in this paper will help to ensure that appropriate and useful interventions and evaluations are developed, which also play an important role in contributing to the development of the field as a whole.

scholarly journals Nanoindentation, EPMA and Atom Probe Tomography Characterisation of Oxygen-rich Layer formed on a Titanium Jet Engine Component

2019 ◽  
Vol 25 (S2) ◽  
pp. 2534-2535
Author(s):  
HM Gardner ◽  
A Radecka ◽  
D Rugg ◽  
DEJ Armstrong ◽  
MP Moody ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Atom Probe ◽  
Jet Engine ◽  
Engine Component

Animation-Based Map Design: The Visual Effects of Interpolation on the Appearance of Three-Dimensional Surfaces

1998 ◽  
pp. 26-34 ◽  
Author(s):  
Stephen Lavin ◽  
Sonja Rossum ◽  
Shawn R. Slade
Keyword(s):  
Computer Animation ◽  
Three Dimensional ◽  
Graphic User Interface ◽  
Visual Effects ◽  
Design Decisions ◽  
Design Alternatives ◽  
Distance Weighting ◽  
Map Design ◽  
Primary Variable ◽  
Inverse Distance

Computer animation is a potential aid in map design, because it provides a means for quickly reviewing many design alternatives. This research is a conceptual exploration of one aspect of animation-based design: The effect of inverse-distance weighting on the visualization of three dimensional maps. The primary variable examined is the inversedistance weighting exponent. Changing the exponent in small intervals allows the creation of a series of three-dimensional maps that can be assembled, and played back as a frame animation. In this procedure, cartographers can view the visual effects of various exponents on the resulting surfaces. Design-based animations allow mapmakers to visualize effects of their decisions in advance of map production and to make more informed design decisions. It is suggested that this method can be expanded to examine map design for a great many forms of cartographic symbology. Ideally, automatic frame generation and a graphic user interface should become an integral part of the development of these visualizations.

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