Product Design – Innovative Trends on Design Philosophies, Approaches, Processes, Techniques, Methods & Standards – Part 2
(a) The Rational Model
The Rational Model was independently developed by Simon and Pahl and Beitz. It posits that:
- Designers attempt to new design or optimize a design candidate for known constraints and objectives,
- Design process is plan-driven,
- Design process is understood in terms of a discrete sequence of stages.
The Rational Model is based on a rationalist philosophy and underlies the ‘waterfall model’, ‘systems development life cycle’ and much of the ‘engineering design’ literature. According to the rationalist philosophy, design is informed by ‘research’ and ‘knowledge’ in a predictable and controlled manner, by keeping technical rationality at the center of the process.
The Rational Model Design Stages
The Rational Model includes the following typical design stages.
- Pre-production design
- Design brief – An early (often at the beginning) statement of design goals
- Analysis – Analysis of current design goals
- Research – Investigating similar design solutions in the field or related topics
- Specification – Specifying requirements of a design solution for a product (product design specification) or service (service specifications).
- Problem solving – Conceptualizing and documenting design solutions
- Presentation – Presenting design solutions
- Design during production
- Development – Continuation and improvement of a designed solution
- Testing – In situ testing a designed solution
- Post-production design feedback for future designs
- Implementation – Introducing the designed solution into the environment
- Evaluation and conclusion – Summary of process and results, including constructive criticism and suggestions for future improvements
- Redesign – Any or all stages in the design process repeated (with corrections made) at any time before, during or after production.
At each design stage of Rational Model there exists many associated best practices.
Criticism of Rational Model
The Rational Model has been widely criticized on two primary grounds.
- Designers do not work this way – extensive empirical evidence has demonstrated that designers do not act as the rational model suggests,
- Unrealistic assumptions – goals are often unknown when a design project begins, and the requirements and constraints continue to change.
Technical or Creative Problem Solving Stages
The Technical or Creative-Problem-Solving Model outlined by Don Koberg & Jim Bagnell, in which designers alternate between: ‘analysis’, ‘concept’, and ‘synthesis’. The latter two sections are often revisited, depending on how often the design needs touch-ups, to improve or to better fit the criteria. This is a continuous loop, where feedback is the main component. To break it down even more, the seven stages specify how the process works. Analysis consists of two stages, concept is only one stage, and synthesis encompasses the other four stages.
- Accept Situation – Here, the designers decide on committing to the project and finding a solution to the problem. They pool their resources into figuring out how to solve the task most efficiently.
- Analyze – In this stage, everyone in the team begins research. They gather general and specific materials which will help to figure out how their problem might be solved. This can range from statistics, questionnaires, and articles, among many other sources.
- Define – This is where the key issue of the matter is defined. The conditions of the problem become objectives, and restraints on the situation become the parameters within which the new design must be constructed.
- Ideate – The designers here brainstorm different ideas, solutions for their design problem. The ideal brainstorming session does not involve any bias or judgment, but instead builds on original ideas.
- Select – By now, the designers have narrowed down their ideas to a select few, which can be guaranteed successes and from there they can outline their plan to make the product.
- Implement – This is where the prototypes are built, the plan outlined in the previous step is realized and the product starts to become an actual object.
- Evaluate – In the last stage, the product is tested, and from there, improvements are made.
Although, the above design process covers up to the last stage of design, it does not mean that the process is over. It is very much possible that the finished prototype may not work as well as hoped, so, once again the new ideas need to be brainstormed and executed upon following the same steps as narrated above.
(b) The Action-Centric Model
The Action-Centric Perspective is a title given to a collection of interrelated concepts, which are antithetical to the Rational Model. It posits that:
- Designers use creativity and emotion to generate design candidates,
- Design process is improvised,
- No universal sequence of stages is apparent – analysis, design and implementation are contemporary and inextricably linked.
The Action-Centric Perspective is based on an empiricist philosophy and broadly consistent with the Agile approach and a methodical development. Substantial empirical evidence supports the veracity of this perspective in describing the actions of real designers. Like Rational Model, Action-Centric model sees design as informed by research and knowledge. However, research and knowledge are brought into the design process by designers – through judgment, common sense & thinking on their feet – more than through the predictable and controlled process stipulated by the Rational Model. In this model, designers’ context-dependent experience and professional judgment takes the center stage more than technical rationality.
The Action-Centric Design Stages
In the Action-Centric Perspective, at least two views of design activity are consistent, and both the views involve three basic activities as described below.
In Reflection-in-Action paradigm, designers alternate between ‘framing’, ‘making moves’, and ‘evaluate moves’.
- Framing – Refers to conceptualizing the problem, i.e., defining goals and objectives,
- Making moves – Is a tentative design decision,
- Evaluating moves – Is a process may lead to further moves in the design.
In Sense-Making-Co-Evolution-Implementation framework, designers alternate between its three titular activities.
- Sense-Making – Includes both framing and evaluating moves,
- Co-Evolution – Is the process where the design agent simultaneously refines its mental picture of the design object based on its mental picture of the context, and vice versa,
- Implementation – Is the process of constructing the design object.
The concept of the ‘Design Cycle’ is understood as a circular time structure, which may start with the thinking of an idea (ideation), then expressing it by the use of visual and/or verbal means of communication (design tools), the sharing and perceiving of the expressed idea, and finally starting a new cycle with the critical re-thinking of the perceived idea. This concept emphasizes the importance of the means of expression, which at the same time are means of perception of any design ideas.
Design philosophy is the study of assumptions, foundations, and implications of design. The field is defined by an interest in a set of problems, or an interest in central or foundational concerns in design. In addition to these central problems for design as a whole, many philosophers of design consider these problems as they apply to particular disciplines (e.g. philosophy of art). Although most practitioners are philosophers, several prominent designers and artists have contributed to the field of design.
Design philosophies are fundamental guiding principles that dictate how a designer approaches his/her practice. Most of the design philosophies are guided by the reflection on two major aspects, viz. material culture (relation between people and design) and environmental concerns (sustainable design).
There are countless philosophies for guiding design as the design values and its accompanying aspects within modern design vary, both between different schools of thought and among practicing designers. Design philosophies are usually for determining design goals, while design goals along with design process practically guide the design. A design goal may range from solving the least significant individual problem of the smallest element, to the most holistic influential utopian goals. However, conflicts over immediate and minor goals may lead to questioning the purpose of design, perhaps to set better long term or ultimate goals.
Great design of modern era is more than just good aesthetics, rather it is the way we use objects. For example an apple watch or Armani’s tailored lines or Gaetano Pesce’s furniture, all are beautiful by themselves, but you can’t truly appreciate their design until you start using them. And after using them, for sure, one would be full of queries, such as, where do these great designs come from? How do designers create objects that are both beautiful and useful? From where do they draw their inspiration? Do they follow any rules, or do they follow their fancy?
The answer to all the above queries is yes; every great designer follows some kind of set rules, generally been referred as design philosophies and few of the best design philosophies of all time are listed as – Function over form, Empathy and focus, Aiming for ‘WOW’, Form and function are one, Deconstructivisim, Simplicity, Design as cultural artifact, Great design is pleasing, Good design redefines itself rapidly, Good design is as little design as possible, which are widely been utilized by most of the great designers of this new era.
A fundamentally improved design approach is an essential requirement for a successful product development, which efficiently organizes the product development process, reduces waste, and provides product to meet customer needs in order to respond to global competition in our own markets, as well as, compete effectively on a global basis. More broadly, a strong design approach enhances integration of product and process design with strategic objectives, improves organizational effectiveness, and provides a framework for effectively implementing design technology.
A design approach is a general philosophy that may or may not include a guide for specific design methods. Some are to guide the overall goal of the design. Other approaches are to guide the tendencies of the designer. A combination of approaches may be used if they don’t conflict.
There have been many design approach models, quite a few of which follows very simple and straight forward approach towards design than the others which follows detailed approach and produces the first time right quality products. Some of the popular design approaches include:
- KISS (Keep it Simple Stupid) design approach – This design approach strives to eliminate unnecessary complications.
- There is more than one way to do it (TIMTOWTDI) – A design approach which follows the philosophy to allow multiple methods of doing the same thing.
- Use-centered design approach – This design approach focuses on the goals and tasks associated with the use of the artifact, rather than focusing on the end user.
- User-centered design approach – This design approach focuses on the needs, wants, and limitations of the end user of the designed artifact.
- Customer proxy design approach – This design approach is based on a theory that there is someone who lives and breathes the product or service in such a totality that it becomes a lifestyle. He or she is then able to take it to the next level in an almost craft like manner all for the good of the end user.
- Critical design approach – This design approach uses designed artifacts as an embodied critique or commentary on existing values, morals, and practices in a culture.
- Service design approach – It is a designing or organizing the experience around a product, the service associated with a product’s use.
- Trans-generational design approach – This design approach includes the practice of making products and environments compatible with those physical and sensory impairments associated with human aging and which limit major activities of daily living.
- Speculative design approach – The speculative design approach doesn’t necessarily define a specific problem to solve, but establishes a provocative starting point from which a design process emerges. The result is an evolution of fluctuating iteration and reflection using designed objects to provoke questions and stimulate discussion in academic and research settings.
Designers have to deal with variety of design considerations in the product design process and his role is to bring together all such different aspects using a strong design approach. For example, consumers look upon a product as something to be bought and used. To the design engineer, it is a technical-physical system that has to function efficiently and reliably. Production engineers have to manufacture it, often in large numbers, preferably fast, cheaper, accurately and with the lowest possible number of faults. A marketer considers it a commodity with added value, something that people are prepared to buy. Entrepreneurs invest in new products and count on an attractive return. People that are not directly involved may see above all the reverse side of the coin: the undesirable and often even harmful side-effects of production and use. To every point of view there are corresponding design requirements and that must be taken into account while designing the product. And, hence, this whole gamut of process requires a multi-disciplinary design approach, which can integrate all such design requirements and ultimately lead to the successful product innovation.
Design method is a widely used term, though conducive to interpretations, it is a shared belief in an exploratory and rigorous method to solve problems through design, an act which is part and parcel of what designers aim to accomplish in today’s complex world.
When design process and design methods are discussed, they tend to be used interchangeably. However, while they are two sides to the same coin, they are different. Design process is a naturally occurring or designed sequence of operations or events over time, which produces desired product design. Design process contains a series of actions, events, mechanisms, or steps, which contain methods. Design method is a way of designing something, especially a systematic way through an orderly arrangement of specific techniques. Each design method possesses a design process.
The role of design methods is to support design work, the aims of which can be varied, though they may include gaining key insights or unique essential truths resulting in more holistic solutions in order to achieve better experiences for end users with products, services, environments and systems they rely upon. Insight, in this case, is clear and deep investigation of a situation through design methods, thereby grasping the inner nature of design things intuitively.
Design method is a broad area, and from a pragmatic standpoint, design method is concerned with the ‘how’ and defining ‘when’ things happen, and in ‘what’ desired order. It mainly focuses on the following five points.
- Divergence – Exploring possibilities and constraints of inherited situations by applying critical thinking through qualitative and quantitative research methods to create new understanding (problem space) toward better design solutions.
- Transformation – Redefining specifications of design solutions which can lead to better guidelines for traditional and contemporary design activities (architecture, graphic, industrial, information, interaction, etc.) and/or multidisciplinary response.
- Convergence – Prototyping possible scenarios for better design solutions that incrementally or significantly improve the originally inherited situation.
- Sustainability – Managing the process of exploring, re-defining and prototyping of design solutions continually over time.
- Articulation – The visual relationship between the parts and the whole.
There is no one way to practice design methods. Also, design method should not be a fixed track to a fixed destination, but a conversation about everything that could be made to happen. And, the language of conversation must bridge the logical gap between past and future, but in doing so it should not limit the variety of possible futures that are discussed, nor should it force the choice of a future that is un-free.
There is a large collection of design methods, techniques, and tools to support all phases of product design innovations. The more common design methods, such as, Computer-Aided Design (CAD), solid modeling, design-by-drawing, brainstorming, and ergonomic analysis, are highly utilized by designers. However, patent searching, features analysis, concept selection, function analysis, among many other of the more rigorous techniques, are least utilized but by a very small fraction of industry. It is further evident that the designers do not make use of simple tools, such as, pareto analysis, cause & effect, control charts, check sheets, and such are perceived by design staff as contributing little to the design & development process and are viewed almost with disdain. There is even reluctance to utilize those design methods that have direct application to design, such as, Total Quality Management (TQM), Quality Function Deployment (QFD), Taguchi Method, Concurrent Engineering Design Method, Design of Experiments, Fault Tree Analysis, Value Analysis & Value Engineering (VAVE), Design for X (DFX) and Failure Mode & Effects Analysis (FMEA). Although these were adopted by certain sections of industry, the adoption by the design industry was generally minimal.
Recent trend suggest that there are quite a few design methods, whose implementation in small industries to large establishments have shown a significant ROI to the organization. Moreover, those are not merely the method but a system by itself as a whole. Some of those design methods are discussed as below.
- Phase-gate method – The phase–gate method refers to the use of funnel tools in decision making when dealing with new product design. ‘Gates‘ or decision points are located at places in the product design process, that are most beneficial to decision making regarding continuance of product design. These production areas between the gates are idea generation, establishment of feasibility, development of capability, testing & validation and product launch. At the conclusion of each of these areas of design of a new product, it is the responsibility of senior management to make a decision as to whether or not the product should continue to be developed. The passing of gate to gate can be accomplished either formally, with some sort of documentation, or informally, decided upon based on the preferences and culture of the organization.
- Demand-pull innovation method – Most of the product designs fall under this method. Demand-pull happens when there is an opportunity in the market to be explored by the design of a product. This product design attempts to solve a design problem. The design solution may be the development of a new product or developing a product that’s already in the market, such as developing an existing invention for another purpose.
- Invention-push innovation method – Invention-push innovation happens, when there is advancement in intelligence. This can occur through research or it can occur, when the product designer comes up with a new product design idea. Best examples are Apple products.
- Flexible design method – Changes are more likely expected on product design according to, what the customer wants, how the customer might use the product, how competitors might respond, and according to new technologies being applied in the product or in its manufacturing process. The more innovative a new product is, the more likely the development team will have to make changes during development. Flexible design is the ability to make changes in the product being developed or in how it is developed, even relatively late in development, without being too disruptive. Consequently, the later one can make changes, the more flexible the process is, the less disruptive the change is, the greater the flexibility.
- Quality function deployment (QFD) – This is an approach to help transform customer needs (voice of the customer, VOC) into engineering characteristics (and appropriate test methods) for a product or service design. It helps create operational definitions of the requirements, which may be vague when first expressed. It prioritizes each product or service characteristic while simultaneously setting development targets for the product or service.
- Lean design method – In recent years, many companies have adopted lean design method with the core idea is to maximize customer value of the designed product, while minimizing waste, and boost efficiency. Lean simply means creating more value for customers with fewer resources. Lean design method utilizes a set of tools. Those tools have to be implemented in the organization to set the goals of lean as improving quality, increasing efficiency by eliminating waste and decreasing costs, but they also lock in product attributes too early and limit innovation.
- Design for six sigma (DFSS) – DFSS approach is used for product or process design in contrast with process improvement. Measurement is the most important part of DFSS tools, where DFSS focuses on gaining a deep insight into customer needs and using these to inform every design decision and trade-off. There are different options for the implementation of DFSS. DMADV, define – measure – analyze – design – verify, is sometimes synonymously referred to as DFSS, although alternatives such as IDOV (Identify – Design – Optimize – Verify) are also used.
- Agile Design method – Agile means – emend of speed, flexibility, innovation, quality, proactively and profitability through the integration of reconfigurable resources that must be achieved in synergy. Quickly react to change by reconfiguration of products, processes and organization structure. The goal of agile product design is to achieve rapid and frequent iterations with multiple design options up front – driven by continuous testing and granular customer analyses – in order to optimize, balance, and priorities requirements and identify risks earlier. This early stage of the process has four primary characteristics: rapid and iterative development model, modular architecture, early risk identification, and intensive supplier involvement. Agile design method that can rapidly introduce a steady succession of incremental product design, which can be called ‘new’ products – that are really planned ‘variations on a theme’, based on common parts and modular product architecture. This capability results in ultra-fast time-to-market, much faster than possible with independent products that do not benefit from product-family synergies in design and manufacturing. Agile product design method is capable of addressing frequent iterations of multiple design options early in the process, based on continuous testing and highly sophisticated customer driven design changes. This method, which both encourages flexibility and recognizes the unpredictability of the early stages of product design, ensures that the latter part of the cycle is much less uncertain, enabling companies to bring more popular products to market at lower cost, and with fewer delays.
Design method is challenging to implement since there are not enough agreed-upon tools, techniques and language for consistent knowledge transfer. While there are many conceptual models and frameworks, there needs to be more granularity of tools and techniques. There are also many variables that affect outcomes since logic and intuition interplay with one another. Therefore, two people even though uses the same design method but arrives at different outcomes.
About Guest Author:
Dr. Subhash Dev Hiwase, Ph.D. (Mechanical Engineering), IIT Kharagpur, India
Dr. Subhash Dev Hiwase, is a Global Professional Leader, doctorate from IIT Kharagpur, India, in Mechanical Engineering, and having 25 years of Extensive Experience on Global Product Development, Strategy & Operations – broadly in the area of New Product Development, Continuous Product Improvement, Technology Innovation, Lean Transformation & Performance Optimization.
He enjoys Designing, Developing & Introducing New Products in the Market, which are having very High Customer Values and has a successful record of creating large/small Product Development Programs, Developing Strategies, Cultivating High Performance Teams and Fortune 500 Client Relationships. Additionally, Subhash has an extensive Financial background and significant International Business Experience.
If any organization/individual is willing to design & develop New Product, which should be Cost Effective, High Quality & within Specific Timeline in India or Abroad, please feel free to reach him at email@example.com.
He has got very strong product design & development credentials and has already developed/worked-on several New Product Development for Automotive, Aerospace, Industrial Product, Heavy Engineering, Consumer Goods, Medical Product, Energy & Power, Oil & Gas, Special & General Purpose Machines Industries for Indian & International OEM’s, such as, In Automotive: He has designed & developed Car, SUV, Bus, Truck, Tractor, 2,3-Wheeler, engines, power transmission, Steering, Clutch, Brakes, Suspensions, Chassis, etc; In Aerospace: He has designed & developed Primary, Secondary & Tertiary Structure, Critical Load-Bearing Structures, Wing Spar, Fuselage Keel Beam, Empennage, Control surfaces, Crew & Passenger Seats, Pressurized Cabin Doors, Fairings, Cowlings, Baffles, Non-Load-Bearing Structures, Un-pressurized Cabin Doors, Access Panels, Armrests, Instrument Panels, Pneumatic-Hydraulic-Electrical Lines, Brackets, Clips, Hooks, etc; In Heavy Engineering: He has designed & developed Cranes, Track Type Tractor, Wheel Loaders, Excavators, Compactors, Motor Graders, Mining & Off-road Heavy Machines, etc; In Industrial Product: He has designed & developed pumps, compressors, fans, blowers, engines, power transmission, gear drives, bearings, couplings, industrial chain, torque limiters, clutches, locking & clamping devices, brakes, backstops, freewheels, and solid-state motor switches, switch-gears, conveyor components, etc; In Consumer Goods – He has designed & developed Mixer, Grinder, Washing machine, Vacuum cleaner, Electronic Toothbrush, Epilator, Trimmer, Massager, Refrigerator, Suitcase, Television, Table Fans, Table Phones, etc. In Medical Product – He has designed & developed X-ray system, Leproscopic surgery products in plastics, Surgical Imaging, Surgical Equipment, Angiography Equipment, Electrocardiogram, etc; In Energy & Power – He has designed & developed ESP, Design Safety, Na Combustion, Cement & Minerals, Building Material, Filter Bags, Reverse Bag Filter, Boilers, etc; In Oil & Gas – He has designed & developed oil rig design, development & quality inspections, etc; In Special & General Purpose Machines – He has designed & developed special purpose, general purpose, lathe machines, and several other machines widely used in the industries etc.