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A design task usually begins with a phase where requirements and objectives are defined. Then, it continues through a creative and iterative process of generation, evaluation, and modification of design alternatives until the design team is satisfied. The main objective of this paper is to expand the concepts of interactive multi-objective design in the field of architecture design, and demonstrate the contribution of parametric modeling, genetic algorithms, computational simulation and an interactive programming environment in the process of decision making in the preliminary stage of architecture design. In this paper, an interactive GA-based computational method is employed to consider both technical and non-technical requirements in exploring the design solutions of a one-bedroom house unit. The design objectives, in this case, include thermal performance, material cost, and the resident’s lifestyle. Ultimately, it is shown how the interactive approach of the exploration method can help the decision maker with objective trade-offs.
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The International Journal of Design Management and Professional Practice
Volume 11, Issue 3, 2017,
© Common Ground Research Networks, Anahita Khodadadi, All Rights Reserved
ISSN: 2325-162X (Print), ISSN: 2325-1638 (Online) (Article)
GA-Based Design Exploration of a House:
An Interactive Computational Approach
Anahita Khodadadi,
University of Michigan, USA
Abstract: A design task usually begins with a phase where requirements and objectives are defined. Then, it continues
through a creative and iterative process of generation, evaluation, and modification of design alternatives until the
design team is satisfied. The main objective of this paper is to expand the concepts of interactive multi-objective design in
the field of architecture design, and demonstrate the contribution of parametric modeling, genetic algorithms,
computational simulation and an interactive programming environment in the process of decision making in the
preliminary stage of architecture design. In this paper, an interactive GA-based computational method is employed to
consider both technical and non -technical requirements in exploring the design solutions of a one-bedroom house unit.
The design objectives, in this case, include thermal performance, material cost, and the resident ’s lifestyle. Ultimately, it
is shown how the interactive approach of the exploration method can help the decision maker with objective trade-offs.
Keywords: Genetic Algorithm, Interactive Approach, Performance Based Design, Building Simulation
esign tasks usually begin with a conceptual design phase where requirements and
objectives are defined and synthesized into design alternatives (Pahl, et al. 2007). In a
traditional approach, the decision making is mainly based on the designer’s insight, basic
functions, and aesthetical aspects. Limited range of performances are evaluated, and this
increases the amount of post-engineering adjustments in the phase of design development
(Turrin, von Buelow and Stouffs 2011). Wang believes 75% of the product life-cycle cost is
determined during the preliminary phase of design (Wang 2002). Similar statements highlighted
the importance of numerical evaluation of the building performance in the conceptual design
phase. Thus, Computer Aided Conceptual Design approach came into play to prevent designers
from investment in poor design alternatives (Turrin, von Buelow and Stouffs 2011). Several
parametric tools and computational exploration methods such as Rhino plugins,
GenerativeComponents, StructuralComponents, and GeometryGym have been developed to
support the designer considering multiple objectives such as structural and environmental
performance, costs and architectural proportions in the early design stage (McNeel Europe.
2017a.; Geometry Gym Pty Ltd. 2017; Rolvink, Breider, and Coenders 2010; Bentley Systems
Inc. n.d.). Furthermore, some conceptual design tools provide a repeated cycle of divergence and
convergence to generate the widest possible range of alternatives and, at the same time, make it
possible to meaningfully manage the search space (Liu Y. C., Bligh and Chakrabarti 2003; Cross
1994; Pugh 1991). There, usually, the link of parametric modeling and evolutionary search
algorithms are employed. Parametric modeling, based on the consistent structure of dependencies
within a problem, allows generating a population of solutions conveniently and relatively fast.
An evolutionary algorithm, mainly a genetic algorithm (GA), provides the iterative process of
form generation, evaluation of solutions using a “fitness function,” modification of the
population until the designer is satisfied (Mendez Echenagucia 2013).
In this paper, the link of parametric modeling, computational simulations and a genetic
algorithm is represented through the early design stage of a one-bedroom housing unit. The focus
of the study is on the interactive procedure of form exploration that allows consideration of both
technical and non-technical requirements. In the following sections, first, the geometric
Corresponding Author: Anahita Khodadadi, 2000 Bonisteel Blvd., Taubman College of Architecture and Urban
Planning, University of Michigan, Ann Arbor, Michigan, 48109-2069, USA. email:
parametrization of the problem is described. Then, it is explained how the parametric model
supports the evaluation of performances including thermal demands and material cost.
Second, an interactive GA-based form exploration method called ParaGen, initially introduced
by Peter von Buelow (2007), is represented. In the section following that, it is discussed how
interactive approaches, such as ParaGen, assist the designer to make trade-off decisions among
various preferences.
Parametric Modeling
Figure 1: The Configuration of the House Unit
Source: Generated by the Khodadadi
A house is not merely a physical space. Its layout and configuration express “the meaning of
a home as a social unit” (Rapoport 1969). The house in this design task is to be occupied by a
maximum of three residents. The geometric configuration processing of the house unit is carried
out using Grasshopper, a plugin for Rhino (see Figure 1) (McNeel Europe. 2017b). Meanwhile,
DIVA plugin for Grasshopper, see (Solemma n.d.), and RS Means Cost Works, see
(RSMeansOnline 2015), are utilized to accomplish the thermal analyses and cost estimation
respectively. To run the thermal analysis using the DIVA plugin, the occupancy is set to be
residential. The weather file is based on Chicago, IL, OHare.Intl.AP data. The run period is
chosen to be annually, and the energy demands for heating, cooling, interior artificial lighting
and the total energy demand are the outputs.
Table 1: The Values of Some Parameters Used in Thermal Analysis of This Project
Acceptable Interval
The density of the people in the room:
Number of Residents ÷ Floor Area
Number of residents = [1,3]
Internal heat gain from light (W/m²)
Equipment load: Internal heat gain from
equipment (W/m²)
Set point heating
20 C
Set point cooling
26 C
Htg COP (COP or efficiency heating unit,
heat pump 3.5, boiler 0.95)
Clg COP (COP or efficiency cooling unit,
compression chiller 2.5)
Infiltration rate building envelope, Air
change per hour ACH
Fresh air supply mechanical ventilation
Source: Generated by the Khodadadi
Table 2: The Building Components Material and Their Assembly
Gravels = 2 cm
Plywood or wood panels = 0.75cm
Insulation board = 2 cm
Plaster: Gypsum board = 0.5 cm
Carpet = 0.25 cm
Lightweight concrete = 6 cm
Stone, sand and gravel 2240 kg/m³ = 4 cm
Wood siding = 0.5 cm
Plywood or wood panels = 0.5 cm
Batt Insulation = 5.5 cm
Plaster: Gypsum board = 0.5 cm
Glass material with 0.4 (Btu/hft²°F) U-value, 0.5 Solar Heat Gain Coefficient (min=0 and
max=1) and 0.5 Visual Transmittance (min=0 and max=1).
Source: Generated by the Khodadadi
The values of parameters required for thermal analysis were set in the Grasshopper model,
and the building components assembly (Ching 2001) is described in table 1 and table 2
respectively. Using the RSMeans Cost Work 2015 database, the Cost Data is set to “Residential
Square Foot Assembly,” the Labor Type and the Location are chosen to be “Residential” in
Chicago. There are many items such as site work, excavation, constructing the utility trench,
septic, interior fixtures and services, plumbing, HVAC, electrical, and protection that should be
considered to compute the actual building cost. In this study, only the costs of the items that are
dependent on the areas of the unit components are taken into account. Those items that cost the
same in all the units, such as the cost of the two interior doors, are also excluded. Similar to
many parametric models, the independent values of the variables in this problem are inputs, and
dependent variables are computed by receiving data from their related attributes, see (Turrin,
Kilian, and Sariyildiz 2009) for further discussion in this field.
ParaGen: A GA-Based Form Exploration Method
Within the preliminary phase of design, the designer is more engaged with reasoning,
argumentation, and decision-making (Rolvink, Mueller and Coenders 2014). Similar to sketching
on a tracing paper and examining different layouts of spaces, the designer needs to gather
information about the performance of each design alternative presenting to the client. Therefore,
some models are needed to be generated, evaluated and modified through an iterative procedure
to approach finally the ideal solutions that meet the design objectives. The described procedure
demands a considerable amount of time and effort and may cause exhaustion, mind blocking and
stop the designer exploring further possible solutions (Cross 2004). Hence, computational
research tools are developed to be utilized within the design process. They can facilitate
evaluation of a greater number of alternative solutions in diverse aspects, and allow the designer
to explore more possibilities.
Among an immense number computational search tools and search algorithms, evolutionary
algorithms can be traced back to the early 1950s when they were used by several biologists.
Within 1960 and 1970 genetic algorithms were developed at University of Michigan under the
direction of John Holland (Dasgupta and Michalewicz 1997). In 2006, at the World Congress on
Computational Intelligence, evolutionary multi-objective optimization (EMO) was recognized as
one of the three fastest growing research fields among all computational intelligence topics (Deb
2008). The reasons for this popularity were mentioned to be:
No requirement for derivative information;
Relative simplicity of implementation;
Flexibility and a widespread applicability.
A genetic algorithm is population-based search method, where stochastic operators are utilized to
generate multiple good solutions. The variables of the parametric model are analogous to genes
and chromosomes. Mechanisms such as selection, recombination, and mutation are employed to
generate solutions and transmit the characteristics of a pair of solutions to the new offspring (Deb
2008). In this research, a Non Destructive Dynamic Population GA (NDDP GA) is used (von
Buelow, 2012). In an NDDP GA, the selection takes place at the population level. A population
of solutions is selected from a database of all current solutions using a SQL query. Next, two
parent solutions are randomly picked from the selected population to generate a new child
solution. The goal is to find an array of good solutions. In multi-objective problems, there is no
single “best” solutions. “Good” may be found on a Pareto front or in clusters. ParaGen is well
suited to explore these sets of good solutions using post processing graphic tools.
In this study, the ParaGen method is used to accomplish the form generation and
exploration. ParaGen steps of form exploration can be described as follows (von Buelow 2012)
(Khodadadi and von Buelow 2014):
1. The design problem is described in terms of parametric variables: a “chromosome.” The
house unit configuration is described in 27 geometrical variables, and several
parameters define its thermal performance and material cost. All these parameters build
a solution’s characteristics;
2. Initial, random values are assigned to the geometrical variables. An initial pool of
solutions is generated, and after evaluating their performance, all parameters of each
solution are stored in a database on the server;
3. A population of parents is dynamically pulled from the solution pool using the
determined criteria: the fitness function in the form of a SQL query;
4. Two parents are randomly chosen from the selected population;
5. Based on the HUX method (Syswerda 1989), a child is bred from the parents and may
inherit some characteristics of one parent or that of the other one. It is also possible that
a combination of some characteristics of both emerges for the child's chromosome. The
HUX principles are shown in figure 2. (Syswerda 1989).
Figure 2: A Schematic Demonstration of Half Uniform Crossover (HUX).
Source: Khodadadi, von Buelow 2014
6. The chromosome (the values of the 27 geometrical values) of the child is processed into
a geometric solution (in Rhino + Grasshopper);
7. The performance of the solution is evaluated using various simulation software. In this
study, DIVA plugin in Grasshopper is used to evaluate the thermal performance. Since
the parametric model is built in the Grasshopper environment, using the DIVA plugin
for Grasshopper facilitates the process and saves time. The material cost is also
estimated using an equation in an Excel spreadsheet;
8. The resulting performance values, which are the thermal and lighting outcomes, along
with the geometric values, are uploaded to the database. Images are also included and
linked to the solution.
Through an iterative process, steps 3 through 8 will take place until satisficing solutions are
found. The solution database and design interface are located on an internet server whose
interface is a web site. The designer takes the first step and defines the configuration of the house
unit parametrically. In step 2, a C code along with a PHP script on the server are used to generate
random values within the acceptable range of each variable. When these values are assigned to a
solution, its thermal performance and material cost are evaluated, and along with the geometrical
characteristics are stored in the database. In fact, step 2 repeats a sufficient number of times to
create the initial pool of solutions. Steps 3, 4 and 5 are taken using the C and PHP codes. Figure
3 illustrates the process of form exploration of the housing unit.
ParaGen is based on a Non-Destructive Dynamic Population GA approach. None of the
defective or poor performing solution is removed (killed off) from the database. Therefore, if the
design criteria are changed, the solutions previously known as defective and poor ones may also
come into play. Also, ill solutions may inform the designer as to what makes a good solution
(von Buelow 2013).
Figure 3: A Scheme of the Paragen Method Used for Computational Search in Architecture Design of a Housing Unit
Source: Generated by the Khodadadi
Interactive Exploration Approach
Within the design task, there are some subjective goals, such as beauty and peace, that cannot be
parameterized. Also, the suitability of the solutions regarding some subjective preferences cannot
be measured or numerically evaluated. One person may find a certain amount of area small, but
another one may not. Hence, it is a privilege for an exploration method if the decision maker
(DM), who might be the designer, the user or the client, can progressively be engaged with the
exploration process, and specify and express a preference at each iteration. Therefore, some
techniques such as visualization are developed to help (Miettinen, Ruiz and Wierzbicki 2008).
The ParaGen method provides this desirable interaction in three ways. First, it allows the
designer or decision maker to specify or adjust a preference, and (re)define the fitness function at
the beginning of each set of iterations. Second, the ParaGen web interface allows the user to filter
and sort the solutions based on any combination of geometry or performance data (von Buelow
2012). Similar to utilizing a telescope to observe one or some specific stars, the ParaGen web
filters can be applied to focus on a well-performing set of solutions. Thus, the designer can
inspect this manageable quantity of filtered solutions and make selections for further breeding if
it is required. Third, ParaGen improves the readability of the information by two visualization
1. The web interface provides both images and key performance values associated with
each solution (von Buelow 2012). The images may display the geometrical
configuration of the solutions or diagrams indicating some certain performance
assessments (see Figure 4).
2. The ParaGen website provides post processing though scatter point graphs of solution
clusters or Pareto fronts and parallel point graphs. These tools combined with graphic
image arrays as shone in Figure 4, help the user explore the most desirable solutions
(von Buelow 2012). In a graph, the points shown represent solutions that have been
filtered by a certain set of criteria.
Figure 4: The Set of Solutions That Have a Maximum 30 M2 Living Room Area
and a Maximum 6 M2 Living Room Window
Source: Generated by the Khodadadi
Discussion about Trade-off and Decision Making
Through a multi-objective design task a set of alternatives will be provided, then the designer
makes the final decision and chooses the most preferred one. Within the decision-making
process, there is usually a trade-off among the design objectives, which is an exchange of loss on
one aspect and gained benefits in another aspect (Miettinen, Ruiz and Wierzbicki 2008). The
Pareto optimal front allows for studying the suitability of solutions regarding some quantitative
values. As an example, the Average Heating Energy demand of the units designed for two
residents and the corresponding values of the Material Cost may be studied. Figure 5 displays a
plot where all the solutions with any amount of total floor area are included. Then, one may
search for a solution that is less expensive regarding Material Costs and, at the same time, has
less Average Heating Energy demand. It is possible to study other properties of each design
alternative such as total floor area while clicking on the corresponding point on the graph and
choose the most suitable solution.
In this paper, the emphasis is on the benefits of the interactive approach of ParaGen that
enable the designer to make a better decision regarding the qualitative design objectives. User’s
lifestyle and personal preferences may vary in each design case. Thus, a design solution that is
the most suitable for one may be inappropriate for the other. Among the provided solutions in the
given example, one scenario might be a couple who enjoy serving their guests at home and desire
a house with a large living room of at least 40 m2 area. Additionally, they may prefer to have as
much daylight as possible, but not be exposed to the outside. They may also think of having a
large balcony where they can stand or sit and look at the garden. They may look for a house with
less average total energy demand and set 26000 kWh as a filter to find a good solution. Also, the
material cost, as a portion of total cost of the house may be critical for them, and 65000 USD
might be set as a limit. Table 3 shows the suitable filtering criteria and Figures 6 and 7 display a
suitable solution regarding the described lifestyle and preferences.
Figure 5: The Average Heating Energy Demand vs. the Material Cost of the Units Designed for Two Residents
Source: Generated by the Khodadadi
Table 3: The Set of Filters which Include Performance Values and Lifestyle Considerations
Acceptable value
40 m2 /
323 ft2
Area of living room window
2.5 m2 /
6.5 ft2
Z coordinate of the living room window
60 cm /
2 ft
Balcony depth
50 cm /
21 ft2
Bathroom area
4 m2 /
2 ft
Average Total Energy Demand
26000 kWh
Material cost
65000 USD
Source: Generated by the Khodadadi
Figure 6: The Furnished Plan of the Suitable Unit
Source: Generated by the Khodadadi
Figure 7: Solution 374, the Suitable Solution
Source: Generated by the Khodadadi
Figure 8: The Average Total Energy vs. Material Cost—Solution 374 is Highlighted in the Graph.
Source: Generated by the Khodadadi
Figure 8 illustrates the preferred solution, with the ID 374. The graph presents the Average
Total Energy vs. Material Cost among the house units with a living room area greater than 40 m2
and minimum 50 cm balcony depth. The graph indicates that the solution is significantly energy
efficient and, also, affordable for the residents. On the other hand, other residents may have
different preferences. They may not have large gatherings in their house and prefer a unit with a
smaller living room that needs less effort to be cleaned up and arranged. Also, they may look for
a unit with less exposure to outside view. Then, filters may be determined differently, and a set
of alternatives displayed in Figure 4 may be more suitable for them.
If a specific filter doesn’t provide any solution, or a broader variety is demanded, it is
possible to set the fitness function to minimize or maximize a particular property. For example,
one may set the fitness function to minimize the cost and restrict the Average Heating Energy of
the newly generated solutions between 100 and 3000 kWh. In Figure 9, the solutions which
emerged after 6 iterations are highlighted.
It is also possible to search for solutions using Pareto sets. A Pareto set itself can be simply
used as the selection population for breeding new solutions. This allows to focus on certain areas
of the set and generate more new solutions within limiting criteria (von Buelow 2017; Emami,
Giles and von Buelow 2017). Figure 10 illustrates a Pareto front (level 1 in a red) where the total
area of windows and the total energy demand are compared. If one may want to search more
solutions with less total energy demand and greater window area, this Pareto set can be used in
the breeding population. The width of the solutions set can also be increased to include more
solutions (see Figure 11).
Figure 9: The Generated Solutions with Minimized Cost and the
Average Heating Energy is between 100 and 3000kWh
Source: Generated by the Khodadadi
In short, in multi-objective design projects where building performance, aesthetic issues,
stability, costs and construction requirements and designer’s or user’s preferences should be
considered, the evolutionary form exploration method seems to be a helpful means of decision
making. The application of a genetic algorithm through the form generation and exploration
process allows setting the fitness function regarding the design objectives and achieving better
solutions in few runs.
This research work contributes to the development of the existing method, ParaGen. This
design search method is based on providing several suitable solutions instead of one single best
solution. Then, it is possible to consider subjective issues and make appropriate decisions. In this
paper, the benefits of ParaGen interactive approach have been discussed. Accordingly, a one-
bedroom housing prototype was considered, and both quantitative and qualitative design
objectives have been taken into account. It is represented how the Pareto front assists the
decision maker to study the design alternatives and choose the suitable one regarding the
quantitative objectives. Then, the benefits of ParaGen interactive approach, where qualitative
objectives may vary from one resident to the other, have been discussed. The decision maker,
who may be the designer or user, is able to provide information about one’s preferences to set the
fitness functions at the beginning of each iteration. Later, when several possibilities have been
explored, and the design alternatives are generated, the ParaGen visual interface with images
attached to each solution, as well as the provided graphs, allow the designer to consider the
qualitative objectives and to facilitate the objective trade-offs. The strength of ParaGen is that it
is user-friendly enough to facilitate a suitable interaction between the decision maker and the
automated form exploration process. Albeit, the decision maker should either have programming
knowledge or be assisted in setting up the parametric model of the problem. In addition, the
algorithm is flexible for further modifications due to the designer’s aspiration. Furthermore,
similar to other interactive search and optimization methods, the designer also can learn about the
interdependencies of the design parameters and obtain a realistic expectation of final solution.
As the last notation, further work is required in the development of multi-objective design
tasks where both quantitative and qualitative objectives are considered. The focus of this paper
has been on the application of an interactive approach in decision making. Additional studies can
be carried out about the possibility of parametrization of some socio-cultural aspects of design
such as lifestyle.
Figure 10: Windows Area vs. Maximum of Total Energy Demand: A Plot Showing Pareto Frontier Level 1 Set in Red
Source: Generated by the Khodadadi
Figure 11: Windows Area vs. Maximum of Total Energy Demand: A plot Showing Pareto Set Including Level New
Generated Solution Using Pareto Levels 1–3 Set in Red
Source: Generated by the Khodadadi
My thanks to Professor Peter von Buelow at the University of Michigan for all his support and,
also, for providing the opportunity to utilize ParaGen tool to accomplish this study.
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Anahita Khodadadi: Doctoral Candidate, Taubman College of Architecture and Urban Planning,
University of Michigan, Ann Arbor, Michigan, USA
... In the next step of the design procedure, the parametric model of the apartment complex is defined. Then, the database is set, separate models for structural and thermal simulations are created, and the GA-based breeding code is scripted [23,24]. Details of inputs for structural and thermal analyses are provided in Table 3. ...
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This article presents a generative design exploration methodology utilized to assist designers in problem structuring and decision-making in a multi-disciplinary setting. This novel design exploration methodology is based on the hybridization of a genetic algorithm (GA) and the Theory of Innovative Problem Solving (TRIZ). This methodology allows investigation of unexpected solutions, application of innovative ideas for resolving contradictory design objectives, and continuous interaction between designers and the search engine. In this study, the design case of a mid-rise apartment complex is used to examine the capacity of the proposed multi-agent design exploration method. Accordingly, both quality and numeric performance-based values of the design alternatives, including the visual appearance of the complex and apartments’ shadows over one another, structural and energy efficiency, and life-cycle impact of the building’s structural system, are investigated to demonstrate the usability and benefits of the developed method.
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This paper presents a computational design exploration method called GA+TRIZ, which aids designers in defining the design problem clearly, making a parametric model where pertinent variables are included, obtaining a series of suitable solutions, and resolving existing conflicts among design objectives. The goal is to include the designer's qualitative and performance-based quantitative design goals in the design process, while promoting innovative ideas for resolving contradictory design objectives. The method employed is a Genetic Algorithm (GA), earlier implemented in an automated design exploration process called ParaGen, in combination with the Theory of Inventive Problem Solving (TRIZ), a novel methodology to assist architects and structural engineers in the conceptual phase of design. The GA+TRIZ method promotes automated design exploration, investigation of unexpected solutions, and continuous interaction with the computational generating system. Finally, this paper presents two examples that illustrate how the GA+TRIZ method assists designers in problem structuring, design exploration, and decision-making.
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When an architectural design problem is stated, it may take several iterations to evaluate the design alternatives, modify the problem statement and the corresponding solutions and make the final decision. The recursive essence of an architectural design procedure and the designer’s tendency to explore further possibilities increases the use of iterative programming search methods to find suitable solutions. Although there have been successful accomplishments in parametric modeling and evolutionary form exploration methods, the prior step of problem structuring has been developed less. We can still solve the wrong problem correctly. Thus, the step of problem structuring has significant effect on the final design outcome. A common challenge in the application of computational design methodology is to discern the parameters that influence the project outcome. Sometimes the solution may be found around a design parameter that is not included in the parametric model and form exploration procedure. This challenge is more likely when contradictory design objectives exist in a project. Then, the designer may favor one design criterion over the others, or compromise (trade-off) and choose a solution among a group of suitable ones. In such cases, the corresponding Pareto front may be studied to find the best trade-off solutions between two or more performative design objectives. A third approach can be the attempt to eliminate the contradiction innovatively. Accordingly, the designer may apply data mining techniques or clustering and classification algorithms to achieve higher-level information or implicit search goals to make a final decision. In this dissertation, I intend to introduce a design search method that a designer unspecialized in the field of data mining can understand and employ in both the formulation of a design problem and in the exploration of generated solutions. The main goal of this dissertation is to introduce a method which provides better problem structuring and decision making. This computational search method is expected to provide the benefits of the application of a genetic algorithm (GA) and the Theory of Inventive Problem Solving (TRIZ) at the same time. The TRIZ Inventive Principles and the associated Matrix of Contradiction are combined with a Non-Destructive Dynamic Population Genetic Algorithm (NDDP GA) used in the ParaGen method, initially developed by Peter von Buelow, to develop the GA+TRIZ method. The GA+TRIZ method helps the designer build a better parametric model where pertinent variables, not all possible ones but those which will more probably be dominant, are included. Furthermore, following the map of the GA+TRIZ design method can provide higher-level information which is useful in making better decisions when conflicting design objectives exist. To examine the suitability and benefits of the application of the GA+TRIZ search method, four design case studies are carried out using the GA+TRIZ map of work. The cases are chosen from design explorations previously solved using only the ParaGen method. In each design case, the design process and the outcome of the explorations are compared with the corresponding results from in the previous trials with the ParaGen-only procedure. The following four metrics are used to evaluate the application of the GA+TRIZ method: • Diversity and particularity of solutions • Performative cost • Time efficiency • The amount of data provided for decision making The outcome of this research is the description of the GA+TRIZ search method along with examples of its application and all the required codes, scripts, and components.
Conference Paper
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This paper presents a review of existing research, projects, developments and applications in the domain of design tools for conceptual structural engineering. The availability of these tools and research into software for conceptual structural design stages has shown a number of interesting developments over the last past few years. The purpose of this investigation is to understand the requirements for software for the early stages of structural design. It investigates the current conceptual design practice, discusses a number of novel trends, and characterizes the relative effectiveness of the available technologies in relation to the nature of the early design stages.
Conference Paper
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We present an example of parametric modeling of a large span roof and discuss a parametric approach to integrating performance oriented design in the conceptual phase of the design process. In the case study shown here, architectural geometry is related to structural morphology; as part of a larger process, its parameterization aims at supporting further performance related investigations, including thermal aspects, by meaning of both the large scale investigation and a more detailed level of design.
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This paper illustrates the use of a computational form-finding method called ParaGen which aids the designer in the exploration of arrays of good solutions. Although the method is guided by a multi-objective optimization program, the goal is to promote the exploration of the solution space based on designer selected combinations of performance objectives. The digital form generation of the bridges is carried out using Formian, a program which uses Formex algebra to describe a wide array of geometric configurations. This form generation is linked to structural simulation and design software (STAAD.Pro) to determine performance values. Finally, ParaGen is used to build a database of all solutions and guide the exploration based on performance values. Using this database, both visual and numeric characteristics are explored.
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Spatial structures often embody generative systems. Both analog (physical modeling) as well as computational methods have been uses to explore the range of design possibilities. Whereas many of the favored physical modeling techniques, such as soap films or catenary nets, inherently generate forms based on certain performative properties, many of the parametric form generating computational methods derive form based solely on geometry, detached from physical performance. ParaGen has been developed as a tool to explore parametric geometry based on aspects of performance. Within the cyclic structure of a genetic algorithm, it incorporates parametric geometry generation, simulation for performance evaluation, and the ability to sort and compare a wide range of solutions based on single or multiple objectives. The results can be visually compared by teams of designers across a graphic web interface which includes the potential for human interaction in parent selection and breeding of further designs. The result is a tool which allows the exploration of the generative design space based on performance as well as visual criteria.
Engineering design must be carefully planned and systematically executed. In particular, engineering design methods must integrate the many different aspects of designing and the priorities of the end-user. Engineering Design (3rd edition) describes a systematic approach to engineering design. The authors argue that such an approach, applied flexibly and adapted to a particular task, is essential for successful product development. The design process is first broken down into phases and then into distinct steps, each with its own working methods. The third edition of this internationally-recognised text is enhanced with new perspectives and the latest thinking. These include extended treatment of product planning; new sections on organisation structures, simultaneous engineering, leadership and team behaviour; and updated chapters on quality methods and estimating costs. New examples have been added and existing ones extended, with additions on design to minimise wear, design for recycling, mechanical connections, mechatronics, and adaptronics. Engineering Design (3rd edition) is translated and edited from the sixth German edition by Ken Wallace, Professor of Engineering Design at the University of Cambridge, and Luciënne Blessing, Professor of Engineering Design and Methodology at the Technical University of Berlin. Topics covered include: Fundamentals; product planning and product development; task clarification and conceptual design; embodiment design rules, principles and guidelines; mechanical connections, mechatronics and adaptronics; size ranges and modular products; quality methods; and cost estimation methods. The book provides a comprehensive guide to successful product development for practising designers, students, and design educators. Fundamentals are emphasised throughout and short-term trends avoided; so the approach described provides a sound basis for design courses that help students move quickly and effectively into design practice. Engineering Design is widely acknowledged to be the most complete available treatise on systematic design methods. In it, each step of the engineering design process and associated best practices are documented. The book has particularly strong sections on design from the functional perspective and on the phase of the process between conceptual and detail design in which most key design decisions are made. The 3rd edition includes new material on project planning and scheduling. Anyone committed to understanding the design process should be familiar with the contents of this book. Warren Seering, Weber-Shaughness Professor of Mechanical Engineering, Massachusetts Institute of Technology.