Complexity models in design

Complexity is a widely used term; it has many formal and informal meanings. Several formal models of complexity can be applied to designs and design processes. The aim of the paper is to examine the relation between complexity and design. This argument runs in two ways. First designing provides insights into how to respond to complex systems – how to manage, plan and control them. Second, the overwhelming complexity of many design projects lead us to examine how better understanding of complexity science can lead to improved designs and processes. This is the focus of this paper. We start with an outline of some observations on where complexity arises in design, followed by a brief discussion of the development of scientific and formal conceptions of complexity. We indicate how these can help in understanding design processes and improving designs

Don’t Look Back: The Paradoxical Role of Recording in the Fashion Design Process

Although there is little systematic research in academia or industry examining design processes in Fashion, anecdotal evidence, based on self- reports and observations, suggests that designers very rarely record the process of designing. Conversely, benefits and requirements of recording the design process within other domains, such as Engineering and Architecture, are well supported in the literature. This paper attempts to explore the dichotomy of recording and non-recording practice across these fields through a review of the literature, semi-structured interviews and a report on one case study in particular, drawing out further detail. Commonalities and differences are identified and new directions for research proposed

Understanding the relationship between design margins and trade-offs

To achieve an objective designers often need to make trade-offs between multiple parameters. In incremental design or during the design process an additional objective is often to minimise the changes they need to make to meet the objective. This is in particular an issue for systems with product platforms, over individual components are over-designed. This paper argues that designers can think about this problem in terms of the margins on the objective parameters as well as the parameters that are traded-off. This is illustrated with the case study of an engineering cooling system

The reality of design process planning

Most companies struggle with the efficiency of their processes. One contributory factor is the lack of efficient process planning. This paper describes current planning practise in industry, which uses a multitude of different plans in parallel. The units of planning and their resulting plans roughly fall into product plans considering cost, bill of material and procurement considerations; process plans including different milestone, task and activity plans and quality plans. This paper maps out the ownership of these plans, and establishes that organisations work because individuals use more then one plan and have a tacit understanding of the relationships between these plans. The lack of effective plans affects the company through a lack of understanding of process connectivity and in consequence bad communication

Strategic, tactical decisions and information in Rapid Manufacturing supply chain

The efficiency and agility of its supply chain is vital to the commercial success of any product. Sharing strategic and tactical information effectively within the supply chain is often a key factor in achieving this goal. This paper proposes a framework to identify strategic, tactical decisions and information. The framework is used to conduct a sector based analysis of the Rapid Manufacturing (RM) industry. The decisions and information identified include amongst others various supply chain strategies and technical information

Free energy calculations of elemental sulphur crystals via molecular dynamics simulations

Free energy calculations of two crystalline phases of the molecular compound S8 were performed via molecular dynamics simulations of these crystals. The elemental sulphur S8 molecule model used in our MD calculations consists of a semi-flexible closed chain, with fixed bond lengths and intra-molecular potentials for its bending and torsional angles. The intermolecular potential is of the atom-atom Lennard-Jones type. Two free energy calculation methods were implemented: the accurate thermodynamic integration method proposed by Frenkel and Ladd and an estimation that takes into account the contribution of the zero point energy and the entropy of the crystalline vibrational modes to the free energy of the crystal. The last estimation has the enormous advantage of being easily obtained from a single MD simulation. Here we compare both free energy calculation methods and analyze the reliability of the fast estimation via the vibrational density of states obtained from constrained MD simulations. New results on alpha- and alpha'- S8 crystals are discussedComment: 18 pages, 2 figures, submitted to J. Chem. Phy

A simplified computer program for the prediction of the linear stability behavior of liquid propellant combustors

A program for predicting the linear stability of liquid propellant rocket engines is presented. The underlying model assumptions and analytical steps necessary for understanding the program and its input and output are also given. The rocket engine is modeled as a right circular cylinder with an injector with a concentrated combustion zone, a nozzle, finite mean flow, and an acoustic admittance, or the sensitive time lag theory. The resulting partial differential equations are combined into two governing integral equations by the use of the Green's function method. These equations are solved using a successive approximation technique for the small amplitude (linear) case. The computational method used as well as the various user options available are discussed. Finally, a flow diagram, sample input and output for a typical application and a complete program listing for program MODULE are presented

Thermal stability and grain growth behavior of mechanically alloyed nanocrystalline Fe-Cu alloys

X-ray diffraction, transmission electron microscopy, and differential scanning calorimetry were used to study the thermal stability of highly supersaturated nanocrystalline FexCu100−x alloys (10~80. For 60<=x<=80 fcc and bcc phases coexist. Heating to elevated temperatures leads to structural relaxation, phase separation, and grain growth of the metastable nanocrystalline solid solutions. Single-phase fcc and bcc alloys undergo significant strain release but no appreciable grain growth prior to phase separation. After phase separation pronounced grain growth sets in. In contrast, samples in the two-phase region show some grain growth and significant chemical redistribution even at low temperatures. The phase separation of single-phase fcc and bcc alloys proceeds via different mechanisms: fcc solid solutions decompose by forming small Fe precipitates, while demixing in bcc alloys starts by segregation of Cu atoms to bcc grain boundaries before nucleation of Cu precipitates. These results show that the stability and grain growth behavior of nanocrystalline alloys is strongly affected by the microstructure of the material

Towards a change process planning tool

The relationship between a product and its design process is generally complex and not fully understood. When modifying a product, industry still rarely considers the implementation process and its consequences for other design activities in the company, which is hard to assess with conventional planning methods. Although change processes are highly constrained, product and process constraints are not usually considered together or traded off against each other when planning the change. Inadequate assessment and planning of the change implementation process can lead to costly knock-on effects across the product and the design process. This paper argues for a combination of change and process research and discusses requirements for a change process planning tool. It proposes a system for the analysis of the impact of change on the product as well as other company activities. Then, a more informed selection between change alternatives is possible

The spiral of applied research: A methodological view on integrated design research

Abstract not available