David G. Ullman

David G. Ullman
David Ullman LLC

PhD

About

85
Publications
58,099
Reads
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4,406
Citations
Citations since 2016
9 Research Items
1197 Citations
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150
2016201720182019202020212022050100150

Publications

Publications (85)
Article
Full-text available
Article published in Machine Design giving a brief introduction to scrum for hardware. https://www.machinedesign.com/3d-printing-cad/scrum-hardware-and-systems-development#menu
Book
This book is a supplement to The Mechanical Design Process 6th edition (MDP6) adding material on the Scrum framework customized for hardware design. All mechanical design process texts including MDP6 are based on the waterfall, serial design methodology. While it is absolutely essential for hardware systems to be planned and be sequential from the...
Book
This book is about best practices for the design of mechanical products. It is available from Amazon and other sources at a reasonable price.
Book
This book contains a series of case studies that demonstrate how industry makes use of the best practices found in the text The Mechanical Design Process. Case studies have long been used in business schools but only rarely in engineering studies. However, studying how professionals have solved design problems is one window on the design process th...
Patent
Full-text available
The Distributed Electric Ducted Fan Wing concept incorporates multiple electric ducted fans on lifting surfaces configured to provide integrated aerodynamics and propulsion resulting in enhanced aerodynamic characteristics and thus aircraft performance. The concept uses a plurality of electric ducted fans (EDFs) to not only provide thrust, but to a...
Article
Full-text available
Propellers expend power partly to provide thrust and partly to increase the velocity of the air going through it. The energy put into increasing the air velocity is wasted. This "wasted energy" can be put to work by using many small distributed Electric Ducted Fans (EDFs) blowing over a major portion of the upper surface of the wing. The speed of t...
Preprint
Full-text available
The purpose of this paper is to compare and contrast three classes of sky taxis; eVTOL, rotor-craft, and USTOL. This comparison is class specific, not configuration specific. In other words, these results cannot be used to compare two eVTOL configurations but can be used to support near-term decisions about which class of aircraft to target researc...
Preprint
Full-text available
This is the first of two whitepapers on Decision Architecture (DA). This first one focuses on defining DA and supporting why it is important for many types of enterprise decisions. The second white paper explores DA in government and open standards. Standards like TOGAF, FEA and DODAF give structure and process to enterprise design, change and evol...
Preprint
Full-text available
This is the second of two whitepapers on Decision Architecture (DA). The first one focused on defining DA and supporting why it is important for many types of enterprise decisions. This second white paper explores DA in government and open standards. Standards like TOGAF, FEA and DODAF give structure and process to enterprise design, change and evo...
Article
Full-text available
Describes how vortex generators can help to cool the engine on a pusher type aircraft.
Article
Full-text available
In CIA analyst Richard Heuer’s classic work, “The Psychology of Intelligence Analysis,” he identified two primary issues that will undermine intelligence analysts’ assessments if not accounted for and addressed: the need to account for uncertainty and the potential suppression of competing analytical frameworks.1 Heuer attempted to instill in CIA a...
Conference Paper
Full-text available
This paper describes the development and evolution of research themes in the Design Theory and Methodology (DTM) conference. Essays containing reflections on the history of DTM, supported by an analysis of session titles and papers winning the “best paper award”, describe the development of the research themes. A second set of essays describes the...
Preprint
Full-text available
The statement “Design is the evolution of information punctuated by decisions” first appeared in The Journal of Engineering Design in 2001(Ullman 2001). Now, ten years later, Product Lifecycle Management (PLM) has evolved to do a superb job of managing design information and is moving toward robust decision management. This paper explores a decisio...
Article
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Article
Full-text available
The Analysis of Alternatives (AoA) is a process that has been adopted by the Office of Management and Budget (OMB) and the Department of Defense (DoD) to ensure that multiple alternatives have been analyzed prior to making investment decisions. It is an assessment approach to evaluate potential solution sets (material, organizational, structural, o...
Article
Full-text available
The thought of buzzing around the sky, quietly, with no carbon emissions is an enchanting one, and is the promise of electrically powered airplanes. Just plug it in for a couple of hours and go flying. No carb ice, no oil stains, no $4.00 a gallon av-gas. But, how close is this to becoming a reality. In this article, the technologies that are neede...
Article
Full-text available
The status of electric GA aircraft. Kitplanes Nov 2009, pp 15-19
Article
Full-text available
This paper describes the author's 30 year evolution from thinking about parts, assemblies and systems, to a decision-centric view of design. The point is made that product is only as good as the decisions made during its evolution and that these decisions are socio-technical in nature and are based on uncertain, incomplete, evolving and conflicting...
Article
Full-text available
The Observe, Orient, Decide, and Act Loop (OODA) was developed to describe the process needed to win at war. Recently, the OODA Loop has been applied to business and product development as a way to describe decision-making cycles. In these situations, the loop often gets stuck at the D, and the team is reduced to making a sound like OO-OO-OO. This...
Conference Paper
Full-text available
The design process can be viewed as a series of actions for reducing uncertainty in product or system design specifications. At the beginning of the design process, uncertainty is high because the design space has yet to be explored and decisions have not been made. This uncertainty contributes to design risk, risk due to the engineer’s lack of kno...
Article
Full-text available
During every stage of the design process, designers trade off performance, cost, and risk in an evolutionary process whose goal is to find a satisfactory solution. This paper explores a recent method to manage the trade study process especially when uncertainty is pervasive and decisions are a mix of quantitative and qualitative information. We bel...
Book
Full-text available
This book is about how to make technical decisions based on uncertain information. It is out of date and so the author/publisher has made it free to download.
Conference Paper
Full-text available
Capturing and communicating risk and uncertainty for NASA’s low-volume high-cost exploration missions have become the subject of intensive research in the past few years. As a result, a variety of quantitative and qualitative methodologies were developed, some of which have been adopted and implemented by various NASA centers in the form of risk ma...
Patent
Full-text available
To identify the best choice from a set of alternatives, team members select the criteria to be used in identifying the best choice. Each criterion describes at least one feature of the alternatives. Each team member then, for each alternative, defines a target value for the feature of the criteria and sets a level of knowledge about the feature of...
Article
Full-text available
This paper details the progress toward the development of the ideal mechanical engineering design support system. It attempts to look at the gap between the needs of a mechanical engineer and what is currently available on CAD systems. Since the term CAD emphasizes that the computer is an aid to the human designer, this paper is designer-centric. I...
Article
Full-text available
This paper develops the importance of decision-making in the engineering design. It makes the argument that the decisions made, and the information contained in the decision-making effort, are key to managing the design process. Based on this importance, the concept of robust decision-making is developed and 12 steps that are necessary to make robu...
Article
Understanding the information accessing activities of engineering designers has been a topic of considerable interest both to industrialists and researchers alike in forming the basic requirements and specification for document management systems, engineering database management systems and information delivery systems. As part of this effort studi...
Conference Paper
This paper presents an introduction1 to a model of a collaborative working environment which supports distributed team argumentation, negotiation, consensus building and rationale capture. Based on a natural model of team deliberation, this model is the basis for the development of a system that enables team support and the capture of the design ra...
Article
Full-text available
Formal decision support tools are little used in engineering design. This paper explores the reasons for this and presents a method which is tailored to problems characterized by teams of stakeholders with inconsistent views who generate multiple alternatives and criteria, and who work to reach consensus. This method is especially designed to suppo...
Conference Paper
This paper presents an approach for identifying team-roles. The proposed approach is based on the interpretation of a design process in terms of the behavior of the members of the team. Behavior is codified in terms of the team member’s process and physical activities. In this study a collaborative design process was recorded on video-tape and anal...
Article
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Article
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The design of products requires engineers to be knowledgeable about basic features and their functions. This paper develops function/feature relation information used by designers in the plastic injection moulding domain. The basis for the findings are interviews with 27 industrial designers, mechanical design engineers, tool designers and plastics...
Chapter
Design of even simple devices requires decision making based on incomplete and conflicting information. Decisions made early in the design process, when the information is the least refined, can have far reaching consequences as the device matures. To date, there have been few methods to help engineers make these critical decisions. In this paper,...
Article
Full-text available
The design of even the simplest product requires thousands of decisions. Yet few of these decisions are supported with methods on paper or on computers. Is this because engineering design decisions do not need support or is it because techniques have yet to be developed that are usable on a wide basis? In considering this question a wide range of d...
Conference Paper
Engineers, as well as other decision makers, are required to make many decisions as they are designing a product or resolving a problem. At these decision points there are many alternatives and criteria to be considered. Studies of design sessions show that most decisions made during these times are in an ad hoc manner. Greater understanding of the...
Conference Paper
The design of even the simplest product requires thousands of decisions. Yet very few of these decisions are supported with methods on paper or on computers. Is this because engineering design decisions don’t need support or is it because techniques have yet to be developed that are usable on a wide basis? In considering this question a wide range...
Conference Paper
A feature recognition system which allows the computer to capture sketches made by a mechanical designer is described. The system takes the user’s input sketching actions and interprets the collection of 2D geometric elements to extract 3D information from them in terms of mechanical features. A application domain, knowledge representation, the der...
Conference Paper
Design is the evolution of information. This evolution usually begins with an ill-defined need for a product and ends with exact specifications for production, use and retirement or recycling. A number of researchers have hypothesized that capture and reuse of this evolving information has potential for improving the design process and the reuse of...
Conference Paper
This paper explores the meaning and evolution of function and behavior during mechanical design. The paper is based on an example from practice. The goal is to develop a model of the information developed during the design process and thus define the types of data inherent in mechanical design. Beyond the academic interest of defining function and...
Article
Full-text available
This paper presents a taxonomy that provides a basis for characterizing mechanical design methods and theories. The taxonomy has three primary divisions: the environment, the problem, and the process. Each of these factors is further subdivided into its important characteristics. For example, the process is divided into plan, processing action, eff...
Article
Full-text available
This paper traces the evolution of a component of a mechanical design from its initial inception to completion. This research focuses on the interplay of design objects, features, constraints, and design decisions. Based on empirical data extracted from verbal design protocols, a design terminology is developed. Constraints were identified in the p...
Article
Full-text available
Collaborative design projects place additional burdens on design documentation practices. The literature on group design has repeatedly documented the existence of problems in design decision-making due to the unavailability of design information. This paper describes a data representation developed for collaborative mechanical design information....
Article
Full-text available
This paper contains a discussion of United States design theory research. It begins with a definition of a design theory and a brief history of design theory research. This is developed into the factors that affect the research direction and results. The paper concludes with a listing of the types of research currently being persued.
Conference Paper
Collaborative design projects place additional burdens on current design documentation practices. The literature on group design has repeatedly documented the existence of problems in design decision making due to the unavailability of design information. This paper describes a data representation developed for collaborative mechanical design infor...
Article
Full-text available
Design documentation does not typically include all of the information sought by mechanical design engineers. This paper reports on a study of practicing engineers making modifications to existing designs. Particular attention is paid to the design information required to answer questions about the design and to verify and refute conjectures about...
Conference Paper
Full-text available
Article
Full-text available
The fundamental processes of problem solving during the mechanical design activity are presented based on a study of human designers. The designers in this study solve problems by applying 10 specialized actions, called operators, which are grouped into the categories of ‘generate’, ‘evaluate’ and ‘decide’. These operators are applied in unique seq...
Article
Full-text available
This paper is a study on the importance of drawing (both formal drafting and informal sketching) during the process of mechanical design. Five hypotheses, focused on the types of drawings, their necessity in mechanical problem solving, and their relation to the external representation medium, are presented and supported. Support is through referenc...
Conference Paper
This paper gives an introduction to the implementation of a Mechanical Design History. This history is a record of the constraints developed and decisions made in the evolution of a product from initial specification to final, detailed design. This history allows design, management, and manufacturing personnel to query not only the final drawings r...
Conference Paper
Design documentation does not typically include all of the information sought by mechanical design engineers. This paper reports on a study of practicing engineers making modifications to existing designs. Particular attention is paid to the design information required to answer questions about the design and to verify or refute conjectures about t...
Article
Full-text available
A system which allows the computer to capture sketches made by a mechanical designer is described. The system not only recognizes basic design features as they are sketched, but it also builds a feature-based solid model of the artifact. The temporal nature of the capture, one feature at a time, serves to form a feature graph that allows for parame...
Article
Full-text available
Six investigations are compared in which the mechanical design process was evaluated by studying human designers. These studies are summarized on the basis of their purpose and evidence followed by a brief discussion. The conclusions reached in all six studies are then compared to show areas of agreemtnt or disagreement and potential for further re...
Article
Full-text available
This paper describes the task/episode accumulation model (TEA model) of non-routine mechanical design, which was developed after detailed analysis of the audio and video protocols of five mechanical designers. The model is able to explain the behavior of designers at a much finer level of detail than previous models. The key features of the model a...
Article
Full-text available
The Current Computer-Aided Design (CAD) and Knowledge-Based Systems (KBS, expert systems) tools are changing mechanical engineering design. Future development and integration of these technologies is dependent on an understanding of the methodology of the mechanical design process, an area of little study and one that is poorly understood. This pap...
Article
Full-text available
Every industry uses safety factors, service factors, or fudge factors to 'correct' calculations so that a design is 'safe' but not too over-designed. Most such factors are based on experience with similar designs, but the source of many is not known beyond the fact that 'we've always done it that way' and that failures are infrequent. A presentatio...
Article
Full-text available
The first paper on the Variable Inertia Flywheel
Article
The band-type variable-inertia flywheel (BVIF) is introduced and previous development is recited. Three dynamic analyses are presented in preparation for system design. An important conceptual breakthrough is reported in the characterization of the BVIF as not one but two flywheels capable of exchanging mass and energy. Three types of BVIF's are st...
Article
An energy storage flywheel with variable moment of inertia, combining the functions of energy storage and power control is introduced and discussed. The specific configuration addressed is the band type variable flywheel (BVIF). This hollow shell flywheel is packed with long thin bands of flexible material mounted like the main spring in a watch. T...
Article
Full-text available
A flywheel with variable moment of inertia, combining the functions of energy storage and power control is introduced. Potential designs are presented and the basic physical governing equations developed. Examples of the flywheel system powering a constant angular rate, frictional load, and an accelerating automobile are presented. Limitations of a...
Article
A variable inertia flywheel (VIF) system was designed and fabricated to verify theoretical predictions and to evaluate the basic operating characteristics of the concept. A fully controllable VIF, full control over the moment of inertia irrespective of the VIF state, is not practical as the efficiency obtained can be no better than a fixed inertia...
Article
Full-text available
This paper has four goals: The first is to develop the importance of decision thinking. Decision thinking suggests that looking at design or business problem-solving as decision-making is a useful approach to understanding problems and generating a good solution to them. The second goal is to present support for this position based on literature fr...
Article
Full-text available
The design process can be viewed as a series of actions for reducing uncertainty in product or system design specifications. At the beginning of the design process, the uncertainty is high because the design space has yet to be explored and decisions have not been made. This uncertainty contributes to design risk, risk due to the engineer's lack of...
Article
Full-text available
This paper presents an introduction ~ to a model of a collaborative working environment which supports distributed team argumentation, negotiation, consensus building and rationalecapture. Based on a natural model of team deliberation, this model is the basis for the development of a system which enables team support and the capture of the design r...
Article
Full-text available
While many people have shown how mechanical engineers should pursue the problem solving process, little experimental evidence exists that demonstrates how they actually design. A technique from cognitive psychology, known as protocol analysis, has been used to identify the mechanical designer's thoughts. The method is to record engineers' verbaliza...

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I added book I wrote to a project, but only articles show up on the project page. How do I make the book title show? I wrote it about this project.

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To understand and support the mechanical design process.