**2.5 Integration of RE with DFMA**

192 Reverse Engineering – Recent Advances and Applications

Another approach that, integrated with RE, can help analyze the redesign of products, is the

Among the methods to support the design of products that can help to consider the manufacture and assembly during the conception phase, DFMA is used as a support to improve the product concept, or an existing design. After all, the focus of DFMA is to help generate a design considering the company´s capacity, to facilitate the final product

The DFMA aims the project and production planning to occur, simultaneously, from a set of principles. Already in the DFMA redesign helps bring the product the best characteristics of production and assembly, seeking to improve quality and reduce manufacturing and

According to Stephenson and Wallace (1995) and Boothroyd, Dewhurst and Knight (2002), the requirements of the original design should be reviewed to establish the new DFMA quality requirements, always considering the following basic principles of design for manufacturing (DFM) and design for assembly (DFA): simplicity (reducing the parts number, shorter manufacturing sequence etc.); materials and components standardized; tolerances release (avoid too tight tolerances, which imply high costs); use of more processing materials; reduce secondary operations; use of process special features (to take advantage of the special capabilities of manufacturing processes, eliminating costly and

Rapid Prototyping (RP) is an innovative technology developed within the last two decades. It aims to produce prototypes relatively quickly to visual inspection, ergonomic evaluation, analysis of shape and dimension and, as a standard for the production of master tools, to

RP allows designers to quickly create tangible prototypes from their projects, rather than bidimensional figures, providing an excellent visual aid during preliminary discussions of the

Currently on the market there is available a multitude of existing rapid prototyping technologies: Stereolithography (SLA), Laminated Object Manufacturing (LOM), Fused Deposition Modeling (FDM) and Three-Dimensional Printing (3D Printing) (Chen, 2000).

This research focused on the technology of Fused Deposition Modeling (FDM), because it offers lower equipment cost (Kochan, 2000); and as such, it is within reach of small and

The basis of FDM is the deposition of layers on a platform from heated filament, and softening of the material for the creation of the plastic model; simultaneously, other softened wires are forming a support for the free surfaces of the suspended model, providing the

help reduce process time for product development (Choi and Chan, 2004).

design for manufacturing and assembly (DFMA).

**2.3 Design for manufacturing and assembly** 

unnecessary operations); avoid limitations in the process.

assembly (Estorilio and Simião, 2006).

assembly time (Dufour, 1996).

**2.4 Rapid prototyping** 

project with colleagues or clients.

medium enterprises and research institutions.

structure upon which the model can be finished.

In the process of creating a product, from the perspective of concurrent engineering, the activities of each department of the company go, largely, in parallel. There is also a permanent monitoring of the product by the end of its life cycle.

Based on the model analyzed by Pahl *et al*. (2005) (see Figure 1), Souza (2007) proposed a modification on the model in order to include considerations by Ingle (1994), so as to contemplate the development of products using the Reverse Engineering method.

After implementing the Reverse Engineering process, it is necessary to allow the phases to unfold logically within the model. When analyzing Ingle´s proposed work (1994), it can be noted there is a major deficiency when considering the need of manufacturing and assembly; thus, Souza´s proposed model (2007) contends that the fundamentals of DFMA, when included in the analysis of Reverse Engineering, complements the proposal by Ingle (1994).

For the analysis of these need, Souza (2007) generated an eight steps model, as illustrated in Figure 4.

Source: Souza (2007)

Fig. 4. Model proposed for the development of products with DFMA in the Reverse Engineering process

This model does not seek to replace all the phases originally proposed by Pahl *et al*. (2005), but the specific phases of the design development and the process, i.e., the adaptation seeks to optimize the technical process of developing a product, in order to be applied to the existing models, including the redesign of a product, with the expectation of achieving the same final results.

Integrating Reverse Engineering and Design for Manufacturing

reverse engineering approach in a product redesign.

analysis, action planning and evaluation, as Figure 5 shows.

**3. Research method** 

participatory way.

Source: Coughlan and Coghlan (2002) Fig. 5. Approach to action-research

located in southeastern Brazil.

**3.2 Company A** 

**3.1 Research method definition** 

and Assembly in Products Redesigns: Results of Two Action Research Studies in Brazil 195

The main objective of the research presented in this chapter is to analyze the application of a model for the integrated use of the design for manufacturing and the rapid prototyping in a

From this main objective on, it is established a secondary objective, to analyze the results from the application of the cited model to reduce production/assembling time, as well as the manufacturing/assembling costs on the redesign of products from the reverse engineering. As to meet these two goals is necessary the intervention of the researcher in the study object, the research method selected was action research. According to Thiollent (2007), action research is a kind of empirical social research which is designed and carried out in close association with an action or to solve a collective problem and in which researchers and participants representative of the situation or the problem are involved in a cooperative and

The adopted action-research process was that proposed by Coughlan and Coghlan (2002), which includes planning cycles (context and problem), data collection, data review, data

The following two topics will present the conduction of this research in two companies,

The company A, founded in 1991, since 1994 successfully manufactures ovens for baking and for industrial kitchens. The company is a Brazilian national leader in the segment of

The research, conducted from January to September 2009, followed the steps of the

integrated model, as proposed by Souza (2007), mentioned in section 2.5, in Table 2.

ovens for professional kitchens and a reference in the market it operates.

Table 1 provides a brief breakdown of each phase of this model.


Source: adapted from Souza (2007)

Table 1. Stages of the model proposed for the development of products with DFMA in the Reverse Engineering process
