Prototyping is a crucial step in product design and development, but it is also known as the highest sunk cost. The top 20 Research and Development (R&D) department spends 142 billion dollars, yet 40 to 46 percent of this money goes into developing products that cannot even make to the market. Furthermore, the lack of comprehensive and widely accepted prototyping strategies and guidelines challenges the success of design teams in selecting options among a plethora of prototyping methodologies, techniques, and resources. The first shortcoming of current prototyping strategies is that they focus on the prototyping experience or the hands-on prototyping process without paying adequate attention to theoretical guidelines about prototyping factors and theories. The second limitation is the sparse guidelines of practical ‘know-how’ or what tools to use while building the prototype. The third shortcoming is that the existing prototyping strategies do not adequately incorporate the Human Factor Engineering (HFE) guidelines into the design of human-centered products. To address these shortcomings, this dissertation aims to formulate a Pre-Prototyping framework that aids designers in exploring prototyping strategies for human-centered products during the early design process.
The overall objectives of this study are split into primary and secondary research objectives. Three secondary objectives are developed as building blocks of the overarching research objectives. First of all, Chapter 2 addresses the first secondary research objective by exploring how Performance Shaping Factors (PSFs) affect human performance and what prototyping strategies should be employed to capture it.
Next, Chapter 3 addresses the second secondary research objective by proposing a computational prototyping method, which assists the designer in exploring the design space to integrate HFE design principles in the conceptual design process. Finally, the third secondary research objective is presented in Chapter 5, which explores the levels of human product interaction and the fidelity that plays a role in prototyping strategies.
The secondary research objectives helped to gain deeper insight into prototyping for HCD based products. These insights are building blocks to address the three primary research questions and develop the Pre-Prototyping framework. The methodology to develop the Pre-Prototyping framework follows a similar step-by-step approach and workflows common to other prototyping frameworks in the prototyping literature; however, the proposed Pre-Prototyping framework adds HCD guidelines and proactive prototyping strategies by injecting HFE design principles. The distinction between this work and the existing prototyping framework is that the focus is on a Pre-Prototyping strategy rather than a hands-on prototyping activity. The second distinction is that this prototyping methodology is developed by focusing on the human-centered design since most of the existing methodologies concentrate solely on the prototyping experience.
The proposed methodology comprises Prototyping Categories, Prototyping Dimensions, and Prototyping Toolbox along with Human Factor Guidelines. These different areas are combined in a framework that is currently presented using MS Excel User-Form. Designers can use this framework via Excel User-Form to conceptualize Pre-Prototyping strategies based on the specific HCD requirements. The proposed methodology is validated by an experiment that conducts 12 prototyping problems between the Intervention group and the Control group. Independent t-tests are be performed between the two groups. It is found that participants who use the proposed framework develop better Pre-Prototyping strategies than those who do not. In addition to the quantitative test, qualitative analysis is carried out by capturing the prototyping experience and attitude of the designers. Likert Scale and screen recordings data are used to gain further insight into participants' evaluation of the framework. It is discovered that the participants perceived the Pre-Prototyping framework to be helpful and they agree to use the Pre-Prototyping framework for prototyping human-centered products
