Session: 02-01-02: Product and Process Design

Paper Number: 142577

142577 - Availability Based Design (Abd) : A New Methodology for Avoiding Machine Design Failure 

Nowadays modern Machine Designs have not only to pursue many different antagonist technical constraints (That's the multifactorial aspect of the "inverse problem" that design represents) to meet their "technical viability", "technical reliability" and also potential targeted budgets (or the “minimum technically safe reachable budget”), they have also, more and more, to be delivered within a given, shorter and shorter, period of time: they are thus subjected to “availability constraints”.

To try to solve the first technical requirements, some authors analyzed in detail the Design Process and tried to synthesize it through given original approaches (House of Quality QFD, TRIZ, Double Diamond, …). Some especially useful methods are especially described in the German Standard VDI 2221 to VDI 2223 and are based on the work of PAHL & BEITZ (1996, 2008). They were also later completed by a cost approach to assess the Product Design Budget (VDI 2225, 1998), the goals being to qualify adequately and systematically the technical and the economical relevance of new Designs by identifying and strategically weighting their requested main and auxiliary functions. Nevertheless, those methods are valid for "unique designs", “product design at large” of medium to high value goods or machinery, developed in “noncompetitive environments” without strategic deadlines to be fulfilled.

Nowadays highly stressed competitive environments are pulling down (sometimes drastically) targeted or awaited budgets, and, very often, are shortening the requested and contractual delivery times. To answer such new  “Machine Design Challenges”, Designers should be highly skilled (or long terms experienced in the discipline), make use of what is sometimes called “Catalog Parts based Design” and/or, at least, be able to find some “design parades” for meeting the overall Design Problem objectives and constraints.

Based on the original concept of the ”generalized safety ratios”, the current work intends to completely revisit the "Design Process" in order to structure a new systematic, rational and fast design scheme. This "heuristic", initiated on customer specification by specific components selection's criteria allows a quick and methodologic treatment of "variation designs" through a combinatory design scheme of the selected machine elements. The 8 algorithmic steps here followed reduce quickly “large design spaces” of potential design solutions into a shorter ones of “admissible design combinations”. This new approach, named ABD for "Availability Based Design" leads to a “Designer's Dashboard” summarizing technical, economical and availability KPIs. It allows Designer and Project Owner to get a clear, rational and dynamic view of the potential solutions and of the constraints she or he should potentially release or strengthen to find solutions to her or his “Machine Design Challenge”. ABD methodology also lets space to Designer and Project Owner to approach together “optimal solution” and to answer efficiently to the questions : What ?, How Much ? and When ?, modern questions to be solved in highly timely constrained competitive environments. 

To prove the benefits of this new Design Methodology, traditional  Design Process was detail analyzed, main steps and time-consuming bottle necks were identified and characterized. A time model was built and documented by specific Machine Design case studies. Results of traditional and ABD methodologies comparisons show clearly drastic gains : 1) solution space is efficiently refined (~93,97% reduction of design combinations) into a set of available combinatory solutions, technically and costly satisfactory, answering in such a way modern specifications and constraints. 2) Design times needed to find satisfactory solutions through heavy iterations is also strongly reduced avoiding time and mean wastes (Processing time gains up to -88,74% are achieved in comparison to the traditional design process). 3) ABD strongly reduced the number of iteration loops to be potentially done (An average of a factor 3 to 5 !). By sorting potential available, costly and technically satisfactory combinations, ABD also allow Designer and Project Owner to face unplanned risks coming from moderns’ versatile environments.  

An illustration of ABD Methodology and its advantageous characteristics will be given through a case studies of a ball screw drive actuator.  

Presenting Author: Pierre Dupont Schaeffler Belgium Sprl/Bvba/UMONS Faculté polytechnique de MONS (FPMs)

Presenting Author Biography: Author Biography : BS (1992) & MS (1995) in Mechanical Engineering from University of MONS (UMONS Polytechnics), MONS Belgium, DEA in Applied Sciences (Advanced Design Techniques - 1996) from University of LOUVAIN (UCL), Belgium, Executive Master in Business Administration from the Free University of BRUSSELS (ULB – SOLVAY Business School of Management & Economics - 2005), BRUSSELS, Belgium, Pierre has 25 years of Professional Machine Design Expertise for the Schaeffler Group. Since 2003, he is also involved in Machine Design Projects and is Lecturer of Machine Design Projects and Safety of Mechatronic Systems at UMONS, Faculty of Engineering (FPMs) and acts also there as External Scientific & Technical Collaborator of the Machine Design & Material Sciences Departments. Since 2012, he has served as Administrator, Secretary, Vice-President and President of the Failure Analysis Society (FAS) of the ASM International and is effective Member of different Professional Societies such as the ASME, the SAE International, the STLE and the AIMs Alumni & SOLVAY’s Business School where he endorsed also many functions mainly at the international level.
Pierre is currently finishing a PhD on Design Processes at UMONS University (Department GMeca - Machine Design & Production Chair, Prof. Dr.Ir. Pierre DEHOMBREUX), MONS, Belgium and developed this new ABD Methodology.

Authors:

Pierre Dupont Schaeffler Belgium Sprl/Bvba/UMONS Faculté polytechnique de MONS (FPMs)