Scholarly article on topic 'Design for Mobility – A Customer Value Creation Approach'

Design for Mobility – A Customer Value Creation Approach Academic research paper on "Materials engineering"

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Procedia CIRP
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{"Design for Mobility" / "Value Creation" / Foldability / "Ease of Folding" / Cladistics}

Abstract of research paper on Materials engineering, author of scientific article — Tarek AlGeddawy, Mohamed Abbas, Hoda ElMaraghy

Abstract It is a global trend nowadays for manufacturing and service firms to create and increase customer value either during initial design of a product/service or by modifying their existing products/service. When a product already exists, customer value can be increased by adding new qualities/features to a traditional product that would add much needed services while keeping price competitive. Qualities, such as foldability and mobility when product is not in use, are examples of creating and improving customer value. This paper presents a design model that helps designers incorporate foldability, mobility and personalization in a regular product design.

Academic research paper on topic "Design for Mobility – A Customer Value Creation Approach"

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Procedia CIRP 16 (2014) 128 - 133

Product Services Systems and Value Creation. Proceedings of the 6th CIRP Conference on Industrial

Product-Service Systems

"Design for Mobility - A Customer Value Creation Approach"

Tarek AlGeddawy^*, Mohamed Abbasb, Hoda ElMaraghyb

"Mechanical and Industrial Engineering, University of Minnesota Duluth, Duluth, MN, 55812,USA bIntillegent Manufacturing Systems Center, University of Windsor, Windsor, ON, N9B 1K3

* Corresponding author. Tel.: +1-218-726-6810; fax: +1-218-726-8596. E-mail


It is a global trend nowadays for manufacturing and service firms to create and increase customer value either during initial design of a product/service or by modifying their existing products/service. When a product already exists, customer value can be increased by adding new qualities/features to a traditional product that would add much needed services while keeping price competitive. Qualities, such as foldability and mobility when product is not in use, are examples of creating and improving customer value. This paper presents a design model that helps designers incorporate foldability, mobility and personalization in a regular product design.

© 2014Elsevier B.V. Thisisanopenaccessarticle under the CC BY-NC-ND license (http://creativecommons.Org/licenses/by-nc-nd/3.0/).

Selectionandpeer-reviewunderresponsibility ofthelnternational ScientificCommittee of "The 6th CIRP Conference on Industrial Product-Service Systems" in the person of the Conference Chair Professor Hoda ElMaraghy" "Keywords: Design for Mobility; Value Creation; Foldability; Ease of Folding; Cladistics"

1. Motivation

Value creation in products is created in many ways. ElMaraghy H. and ElMaraghy W. [1] showed that creating product variants by introducing new qualities and services can enhance customer satisfaction. They also introduced the different strategies used in order to manage variety, starting from product design up to the manufacturing phase. As an example, the Telecommunication industry has evolved over the past two decades with the introduction of cell phones. [2]. Fig. 1 illustrates how the phone as a product survived by introducing a series of added upgrades, qualities and services. Services like cellular networks and data services accompanied the introduction of qualities like handheld mobility, touch screens and smartphone capabilities in telephones. Landlines used to be the common method of communication; now cell phone users exceed the number of landline users by eight or nine to one [3].

One of the main reasons for this tremendous increase in the number of users is that customers perceived mobility as a main feature of the value proposition of mobile commerce [2]. Furthermore, the innovation of the touch screen as a new

quality preserved the phone success trend and increased its value to customers as a micro-computer, calendar, media player, gaming station, etc. [4]. The ultimate advantage of the introduction of handheld mobility to phones was the personalization of phones, while making them indispensable for millions of customers. Decreasing the dimensions of products is a main enabler for better product mobility. In the case of the telephone, the dimensions of the product itself became smaller due to technology advancement in electronics. However, folding the product, when not in use, can also lead to better mobility, introducing personalization as a new service to ordinary large volume immobile products (Fig. 2).In this case, value creation is increased through better qualities (foldability and mobility), better services (personalization), and better price through reduction of transportation, handling as well as storage costs [5][6]. This paper presents a design model that helps designers incorporate foldability, mobility and personalization in common designs.

2212-8271 © 2014 Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.Org/licenses/by-nc-nd/3.0/).

Selection and peer-review under responsibility of the International Scientific Committee of "The 6th CIRP Conference on Industrial

Product-Service Systems" in the person of the Conference Chair Professor Hoda ElMaraghy"


Introducing Handheld Mobility and 2G Networks

Introducing Data Services and 3G Networks

Fig. 1: The Qualities and Services that Sustained the Phones industry

developing foldable containers in order to reduce the transportation, handling and storage costs of empty containers. Also, Shintani et al. [6] discussed the potential to use foldable containers in order to reduce management costs of the container fleet.

2.2. Simple 2D/3D folding

Mollerup [12] suggested 12 concepts for producing collapsible products. The concepts and examples are shown in Figure 3. Some of the concepts are in fact variants of the same idea, such as: 1) working with soft materials for folding, creasing, bellows and rolling, 2) working with modular design for bundling, assembling and nesting, 3) working with an articulated mechanism using hinging, fanning and concertina, while sliding and inflating are genuine ideas. Group (3) working with an articulated mechanism is of a special interest as it serves a wide range of products which require structural rigidity.

1. Bundling

7. Rolling


Fig. 2: Introducing Mobility to Create Customer Value 2. Literature Survey

2.1. The Need for Foldability and Mobility

Mobility can be created in various ways. For example, imbedding wheels or rollers within a product is highly evident in many applications. Providing compact products can also enhance portability, such as replacing a bulky desktop with a laptop. Another scheme to enhance mobility within a product is modular design that can be easily assembled and disassembled. Varghese et al. [7] showed that their proposed modular dining table scored higher than other alternatives based on the constraint space conditions. Jackson et al. [8] discussed the concept of factory-in-a-box that consists of standardized production modules which can be easily installed and transported to the desired location. This concept is similar to the Reconfigurable Manufacturing Systems introduced by Koren et al. [9]. Khalilbeigi et al. [10] presented a double sided projected displays that can be folded with the aid of predefined hinges, assisting users in manipulating the size and shape of the display using fold gestures. De Temmerman et al. [11] proposed a concept for mobile shelter which is based on the geometry and kinematic behavior of the foldable plate structure. It introduced a new type of joint for connecting bars, which allowed the system to be deployed as desired, while maintaining the degrees of freedom of a plate system. Konings and Thijs [5] discussed new perspectives in

6. Hinging

12. Concertina

Figure 3: Foldability Concepts in Products (Adopted from [12]) 2.3. Complex 3D folding (Origami)

When the needed folding mechanisms becomes complex with multidimensional folding potential, Origami, which represents a mixture of art and science, can be used to develop such mechanisms. Dureisseix [13] illustrated some aspects of origami related to engineering structures and pointed out the recent developments in assembly of repetitive elementary structures such as planar geometrics with tessellations and foldable/deployable structures. Tachi [14] introduced the first practical method to solve the inverse problem of obtaining the

crease pattern for a given polyhedral surface. Deng and Chen [15] presented an origami sheet idea that can be used in designing and fabricating foldable structures by integrating additive manufacturing and silicon molding techniques. Ario et al. [16] created an optimum deployable bridge by adopting an origami folding structure. Greenberg et al. [17] demonstrated the feasibility of finding links between origami and compliant mechanism analysis by presenting four flat folding paper mechanisms as well as their associated kinematic and graph models. Miura and Tachi [8] presented a family of rigid foldable cylindrical polyhedra and showed the symmetry operations used to synthesize the cylindrical structures as well as the space filling tessellation. Ozawa et al. [18] proposed a new design for a 30m light-weight, large deployable reflector, which is made of seven tri-fold deployable truss modules.

2.4. Market Search for Successful Foldability Concepts

The surveyed foldability concepts need to be further analysed to identify with better folding qualities. Eight distinct products are used for this analysis (figure 4). They mainly focus on group (3) that has been identified in section 2.2. Six main features and their states have been identified to contribute in product foldability:

1-Function when installed

1.0-No load

1.1-Intermittent load

1.2-Constant load

2-Reason for folding




3-Folding Mechanism


3.2-Planar Hinged

3.3-Spatial Hinged

3.4-Hinged/disconnect joints

3.5-Hinged/separable parts

4-Mode of operation



5-Unfolding Technique



5.3-Pull and Rotate



6.2-Stops 3-Snap locks



6.6-Non-return mechanism


Each of these eight products possesses some of those foldability features. Table 2 shows the specific features of each example. Cladistics is a hierarchical data clustering analysis that has been extensively used in biology. Cladistics has been used in organizational systematics [19] and in engineering design to identify successful products and their enabling features to succeed [20].

A cladistics analysis has been applied to the eight product examples using 'NONAME' software [21]. The result is a cladogram, a clustering tree diagram, which represents the evolutionary hypothesis of the studied objects. cladogram tree has a root and spans into branches and ends at leaves which are the studied objects. The existence of a branch with several splitting nodes can be considered as an indication for active evolutionary process, and can be followed as the path of success to the end leaf which would be the successful product. The resulted cladogram of the 8 examples shows that a planar hinged design with some disconnect-able joints is the most successful product design among the eight studied products. Furthermore, the most successful features according to the

cladogram in Figure 5 are 1.2 Carrying constant load when installed, 2.3 Used for storage and portability when folded, 3.4 Planar Hinged structure with some separable interfaces, 4.1 Manual folding application, 5.1 Unfolding by pulling, folding by pushing and 6.4 Use latches to secure the structure.

Table 1 : The features of a set of foldable products „ , a Features

1 2 3 4 5 6

A-Radio Antenna 0 1 1 2 1 1

B- Retractable Awnings 0 1 2 2 4 6

C- Foldable Tables 1 2 2 1 1 2

D-Baby Strollers 2 1 2 1 1 4

E- Spiral Display Tower 2 2 3 1 3 7

F- Foldable Animal Cages 2 1 5 1 1 5

G- Foldable Crates 2 3 4 1 1 4

H- Collapsible Crates 2 3 6 1 2 3

A- Radio Antenna

B- Retractable Awnings

Figure 4: Examples of foldable products

Successful 4 Product Features

Figure 5: The Success Map of Collapsible and Foldable Products

3. Design Methodology of Foldable Products

This paper presents a systematic design approach, which lacks in the literature, to guide designers who produce foldable products. In addition, this approach associates foldability with other value creation factors to select the best design among several candidates.

3.1. Foldability Solution Map

Based on the literature survey and cladistics analysis, a foldability solution map is suggested to add the quality of foldability to an existing product. The potential foldable design modifications include either modular or articulated design as indicated in figure 6. For modular designs, modularity analysis would be useful to determine the number of disassembled modules and which parts should be clustered into each module [22]. A packing optimization problem may be used to layout modules in order to minimize the total collapsed volume. For articulated designs, a folding mechanism is needed. For simple 2D foldability, kinematic mechanism design can be applied, while Origami would be more suitable for complex designs.

Figure 6: The Map of Design for Mobility as a Customer Value Creation

3.2. Design Quality

To be able to compare design alternatives, three normalized indices have been developed:

DOF Index = 1 -Foldability = 1 — NOP Index = 1 -


Yj Folded Dimensions Y Original Dimensions


(1) (2) (3)

and manufacturing cost. 3.3. Case Study

A workbench is a standard piece of equipment used in most workshops and homes (figure 7). The back wall is used to mount hand tools for accessibility, while the workbench top is used as a mounting horizontal surface for different work pieces. Adding the quality of foldability, hence mobility, to workbenches would increase customer value by allowing technicians and hobbyists to store their tools at the back wall and move those bulky workbenches around and convert them into personal items.

Mounting Back Wall

Mounting and Work Surface

Unfolded Height

Unfolded Width

Figure 7: A Representation of a Regular Workbench

Design modifications will focus on foldability in the X and Y axes rather than spatial foldability, since this is a rigidity consideration. Since this is a 2D folding problem, an initial articulated design has been developed using a closed-loop kinematic mechanism illustrated by solution alternative (a) in Figure 8 based on synthesis of a 4-bar linkage [23]. All used joints are revolute joints. This is a single degree of freedom (DOF) mechanism that maximizes the ease of folding but it has a poor foldability in terms of folded volume.

Joints and links of the mechanism have been then gradually removed to produce the other design alternatives shown in Figure 8 of different DOF, NOP and foldability. Values of DOF, NOP, their indices and foldability are shown in Table 2. Part thickness t in Figure 8 is neglected compared to part length L. NOP includes both mechanism links and joints. The most modular design alternative (e) has only 4 links (the basic components) and no kinematic joints.

Table 2: The Properties of the Possible Folding Solutions of the Workbench Example

Degrees of Freedom (DOF) of design mechanism affects the ease of folding. The lower the DOF, the more controlled and easier the folding/unfolding processes. Foldability compares folded volumes to original volumes. Number of parts (NOP) is a design feature that greatly affects the ease of manufacturing and the product price represented by material

Model DOF DOF Index NOP NOP Index Original X+Y Folded X+Y

A 1 94 11 0 7L 5L

B 2 89 9 18 6L 3.67L

C 3 83 7 36 6L 3L

D 8 56 6 45 6L 2L

E 18 0 4 64 6L 2L

4L Unfolded _ )

1 Folded

Figure 8: Five possible folding design solutions of the workbench

It can be noticed that DOF index and foldability are indications for the ease and quality of folding in design, while NOP index is an indication for ease of manufacturing. Together, an overall index is introduced to describe customer satisfaction by the newly introduced folding quality, personalization service and better price due to ease of manufacturing. Figure 9 shows the effect of each design alternative on these indices.

The overall customer satisfaction index (CSI) which expresses value creation in this application is expressed as:

CSI = wtx DOFIndex

+w2 x Foldability + w3 x NOPIndex

Where wu w2 and w3 are arbitrary weights

If the weights are set to be equal (1/3 each) then the CSI is the average index of the three indices as shown in Figure 9. The best CSI point is between design alternative (c) and (d), which is an inflection point between articulated designs and modular designs.

100 90 80

70 60 50 40 30 20 10 0 '''

- ■ DOF Index

---NOP Index


-CSI (equal weights)

Modular Design

b c d e

Possible Design Solutions

Figure 9: The relationship between design quality and value creation

In order to determine which of the best design alternatives (c) and (d) provides a better value for the customer, a Pugh chart [24] analysis has been performed (Table 3). The customer and manufacturer related design criteria have been combined in one set, since a new folding design should be appealing to both the user to buy and the manufacturer to adopt and produce. Those criteria include:

1- NOP 3-

2- Number of removable 4-parts 5-

Folding/setup time Folding mechanism. Space saving when folded

The performed Pugh analysis is a general comparison between the articulated design zone vs. the modular design zone. It shows that an articulated design is always preferable over modular ones due to the fact that frequently removable parts tend to be lost, which decreases the customer created value from foldability and mobility. Also having separable parts takes longer time for installing the product and assembling different modules. Based on this result, design (c) consisting of 7 parts and 3 DOF is the best candidate to create the quality of mobility and the service of personalization in the studied workbench example.

Table 3: Pugh Chart of the Workbench Folding Solutions

Alternative Designs

Articulated Modular

•a -o S != O & ^

Properties "2 T5 Ë o a b c d e

Count of parts D -- - + + +

Number of removable parts A ++ ++ ++ - --

Folding/setup time T ++ + - -- --

Folding mechanism U ++ ++ + - --

Space saving when folded M -- - + ++ ++

sum of+ 6 5 5 3 3

sum of - 4 2 1 4 6

Total 2 3 4 -1 -3

4. Conclusions

5. References

Value creation is a function of customer satisfaction, which can be improved by introducing new product variants that have new qualities. This leads to new services and better prices when manufacturability of the product is taken into consideration as well. Adding foldability to a product leads to better mobility and more potential for that product to become more personalized. Increasing ease of manufacturing causes product price to drop and increases the created customer value.

A case study of an ordinary workbench has been introduced to illustrate the proposed model of value creation by foldability. New normalized indices, Foldability, Degrees of Freedom (DOF) Index and Number of Parts (NOP) Index, have been developed to express the quality and ease of the introduced folding feature and ease of manufacturing which directly affects product price. Figure 10 shows that there is also a relationship between the ease of manufacturing expressed by NOP and foldability and DOF Index.

100 90 80 70 60 50 40 30 20 10 0

_ Active Zone ->

- ! - Foldbbility . / --DOF Index

/ / / / / / / / / /

5 7 9 11

Number of Parts (NOP)

Figure 10: The relationship between manufacturability and value Creation

The relationship is a trade-off between foldability in terms of folded volume and ease of folding. Less NOP produces better foldability, however, there is a minimum NOP below which less number of parts does not produce better foldability, and hence there is a lower NOP limit for the active solution zone. The active zone defines the design space in which changing the input parameters, such as NOP, would change the quality of the solution. Less NOP results from modular designs by removing joints between mechanism links. An articulated design on the boundary of modular designs is found to be the most effective alternative for better value creation.

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