International Journal of Current Engineering and Technology E-ISSN 2277 – 4106, P-ISSN 2347 – 5161

©2021 INPRESSCO®, All Rights Reserved Available at http://inpressco.com/category/ijcet

Research Article

Design for manufacturing and Assembly practices in early stage of

product development
Varsha Karandikar1*, Sandeep Bade2 and Supriya Patil2
1Professor, Industrial Engineering Department,Vishwakarma Institute of Technology, India
2Lead Engineer, Manufacturing Engineering Department, John Deere India Pvt. Ltd., India

Received 20 Aug 2021, Accepted 24 Sept 2021, Available online 05 Oct 2021, Vol.11, No.5 (Sept/Oct 2021)

Abstract

This paper gives an overview of research that is expanding the domain of design for manufacturing (DFM) into new
and important areas. DFM and assembly is widely used in industry, especially in product design and development
process. to meet customer needs, companies are struggling with competitive markets to produce low cost products
with high quality and faster to market. It becomes an important concept as the best time to find cost reductions, at
design stage, rather than during manufacturing. The paper concludes with some general guidelines that suggest how
manufacturing firms can develop useful, effective DFM. Overall goal with the paper is to aid designers,
manufacturers, process planners in the practical industries on the ground and researchers in the mentioned area of
study.

Keywords: Design for manufacturing, Assembly, Product Design, Techniques.

1. Introduction Unfortunately, downstream life cycle needs are difficult

to predict accurately during early design phases for
In a context of deep change of industrial market related many reasons. (Swift KG, Brown NJ, 2003)
to globalization and delocalization, being competitive
becomes a challenge for all industries. Developing • The product specifications, dimensions and
successful new products requires the ability to predict, material of the product are not yet finalized, the
early in the product development process, the life cycle manufacturing process and possible risks are very
impact of design decisions. Downstream life cycle unpredictable.
issues include considerations of how the product will • Number the life cycle issues and complexity of each
be made, shipped, installed, used, serviced, and retired cycle that must be considered are crushing.
or recycled. Ignoring downstream issues (or producing • Other side the details of manufacturing, packaging
and servicing may be outside the area of expertise of
poor estimates) leads to poor product designs that may
the designer.
cause unforeseen problems and excessive costs
• The knowledge compartmentalization problem is
downstream. Sometimes, when problems are
further exacerbated by the current trend towards
uncovered during design verification or testing, the locating manufacturing and service organizations
problems can be corrected by redesign, but the cost of overseas. Reducing energy consumption.
redesign at this late stage can be prohibitive.
Sometimes companies must simply accept higher All the above factors contribute to insufficient
manufacturing costs and reduced product effectiveness consideration of product life cycle mainly
resulting from early design errors. manufacturing issues at design time.
If accurate predictions of life cycle needs can be To help designers better assess the downstream life
made early in the design cycle, it allows product cycle impacts of their design adoptions, manufacturer
development teams to create superior designs. This not and researcher have developed many design choice
only reduces the number of redesign iterations, the support tools referred to as Design for X (DFX). The ‘X’
time-to-market, and the development and in DFX represents any one of a variety of design
considerations occurring throughout the product life
manufacturing costs but also improves the customer’s
cycle, such as quality, manufacturing, production, or
experience.
environment. A DFX can take many forms, it could be
*Corresponding author’s ORCID ID: 0000-0002-7847-6928 procedure or a set of guidelines on paper, or it could be
DOI: https://doi.org/10.14741/ijcet/v.11.5.3 a computer program that performs various types of
509| International Journal of Current Engineering and Technology, Vol.11, No.5 (Sept/Oct 2021)
Varsha Karandikar et al Design for manufacturing and Assembly practices in early stage of product development

analyses resulting in cost, manufacturability, or

performance estimates, which are then used by the
designer in making decisions. DFX (design for X)
methods provide approaches that consider a maximum
of product life cycle information during the design
process. A design solution is then the result of multiple
expert product assessments and a collaborative
multidisciplinary decision-making process. Design for
Manufacturing (DFM) and Design for Assembly (DFA)
are two of the most common and popular DFX tools.
Traditionally, DFA methods evaluate the ease of Fig.2Concurrent Engineering
assembly, and DFM methods evaluate the feasibility
and cost of manufacturing the product at the operation Design for manufacture (DFM): It is a product design
level. Recent product life cycle includes incorporation approach that considers design goals and
of DFM techniques at a variety of places in the product manufacturing information as soon as possible in
development process, including conceptual design, product definition. Many studies deal with
prototype design, detail design, and design verification. presentation and implementation of DFM concepts:
The most important result of the paper is a DFM and – Presentation of DFM concepts and tools (Poli C,
different design methods. To understand, How DFM 2001)
techniques address a wide range of manufacturing and – Analysis of manufacturability and providing
life cycle concerns including product quality, solutions to improve design (Lovatt AM, Shercliff HR,
manufacturing system performance, life cycle cost, and 1998 and 0Boothroyd G, Dewhurst P, Knight W,2001)
environmental issues. – Manufacturing processes selection based on
processes classification and attributes comparison.
2. Literature Review Specification of appropriate method and techniques of
materials and processes selection (Swift KG, Booker JD,
2.1 Product Life cycle: 2003)
– Specification of techniques that will reduce cost and
A product life cycle is the amount of time a product ease handling of components (Michele Modena,2019)
goes from being introduced into the market until it's – Providing some fundamental rules of design that
taken off the shelves. There are four stages in a give the “best” solutions for manufacturing point of
product's life cycle—introduction, growth, maturity, view (Pahl G. et al. 2007)
and decline. Fig. 1 shows the product life cycle.
Five principles are examined during a DFM. They are:

• Process
• Design
• Material
• Environment
• Compliance/Testing

In summary, the scientific community proposes many

Fig.1Product life cycle studies of product manufacturability analysis based on
different parameters (tasks, attributes, characteristics,
2.2 Concurrent engineering cost, etc.) but it does not propose a synthesis
(integration) method. Current approaches require pre-
It is also known as simultaneous engineering, is a definition of product geometry and take place late in
method of designing and developing products, in which the detailed design stage, cycle cost, and environmental
the different stages run simultaneously, rather than issues.
consecutively. It decreases product development time
and the time to market, leading to improved 3. DFMA and different stages of concurrent
productivity and reduced costs. The main proposal of engineering
concurrent engineering is to shorten a product
development time through a simultaneous time 3.1 DFM and Concurrent Engineering:
implementation of the several stages of the engineering
activity in parallel and under a concurrent mode Generally, concurrent engineering (and DFM) is
offering all information required by all elements of the accomplished through a iterative “spiral” design
product life cycle. Studies show that the design process (shown in Fig. 3) in which marketing experts,
approaches affect the final cost of a new product more designers, manufacturing engineers, and other
than any other factor. Fig. 2 CE design phases. personnel jump back and forth between identification
510| International Journal of Current Engineering and Technology, Vol.11, No.4 (Sept/Oct 2021)
Varsha Karandikar et al Design for manufacturing and Assembly practices in early stage of product development

of customer needs, design of the product, and design concept is invested with physical form.
assessment of manufacturing issues. Embodiment design is concerned with three major
tasks - product architecture, configuration design, and
parametric design

3.3 Product Architecture

Focus of conceptual design is to find out the

appropriate product architecture which can satisfy the
product concept. To define the product architecture,
one must identify the product elements and their
assembly or linking between these elements. (F.Z.
Krumenauer, C.T. Matayoshi, I.B. da Silva, M.S. Filho,
G.F. Batalha, 2008). Generally, there are two types of
product architecture, modular and integral. Modular
architecture focus on linkage/connection/interaction
between two modules/functions while integral
architecture focus on each module/function its
Fig.3The Design for X Cycle
purpose and inner working.
Barriers to effective DFM and concurrent engineering
3.4 Configuration Design
occur when the people performing marketing, design,
and manufacturing cannot communicate or share
In this method designer develop a product or its
knowledge. The reason could be
element with the help of predefined
components/functions and interaction between them.
• Designers lack detailed knowledge of the current
Configuration design is faster and cost-effective way of
manufacturing practices and the
designing. In this phase designer provides the
• Manufacturing engineers are not available to
definition or dimension or shape to each
provide this assessment,
component/function. (F.Z. Krumenauer, C.T. Matayoshi,
• Designers may not be able to do sufficient
I.B. da Silva, M.S. Filho, G.F. Batalha, 2008)
manufacturing assessments of their designs.
3.5 Parametric Design
Due which the designer will only consider customer,
internal legal and environment requirement while
In parametric design the attributes of components
designing the part and no manufacturing requirements
or barriers. The result may be assurance to a design identified in configuration design become the look
that is unnecessarily expensive to manufacture. Before variables for parametric design. Determining the
the industrial revolution, the salesperson, designer, precise values, dimensions, or tolerances of the
and craftsperson were often the same person. This components orcomponent features that are deemed
person had a detailed understanding of the customer’s critical to quality. (F.Z. Krumenauer, C.T. Matayoshi, I.B.
needs: how the design would meet those needs, and da Silva, M.S. Filho, G.F. Batalha, 2008)
how it would be made. Concurrent engineering Since it's at these stages that decisions regarding
naturally occurred within that person’s head. materials and shapes are made, this can be the
planning stage which has the best influence on the
3.2 DFM in embodiment design: materials flow cycle, production processes that are
used, furthermore as many of the small print. Design of
Embodiment design is well known in product the merchandise in a very modular form allows for
development. Kesselring (1654) was the first to refer straightforward disassembly. The arrangement of the
to embodiment design and introduced the guidelines: general layout can make it easier to perform the
manufacturing costs should be less, optimum required steps in remanufacturing. The principle of
requirements, weights should be low, minimum losses
division of tasks (function separation) utilized in
and optimal handling. ( MS Hundal. 1997). According to
embodiment design (TIMÁR, Imre, Tibor BORBÉLY,
Pahl and Beitz, embodiment design can be described
(1996) as: “it is treated as design process starting from István LISZTES, and Pál HORVÁTH.,2010) should
very initial or concept phase of product. The design concentrate go down parts which might be easily
should be developed in compliance with engineering conditioned.
and economic criteria.” (Dieter, G.E., 1991). It is a The final design phase will finish the event of the
process where the structural development of the products. At the top it's to be completely defined. For
design concepts takes place. And in this phase that this process, the engineer has helpful principles,
decisions are made on strength, material selection, size guidelines and also the three basic rules: simple,
shape and spatial compatibility besides, where the unambiguous, reliable.
511| International Journal of Current Engineering and Technology, Vol.11, No.4 (Sept/Oct 2021)
Varsha Karandikar et al Design for manufacturing and Assembly practices in early stage of product development

• Unambiguous: -The use of product has got to be manufacturing. Currently, Six Sigma approaches
clear and uncomplicated (fulfillment of technical promote the characterization and classification of
function) manufacturing processes, with downstream statistical
• Simple: - There aren't any unnecessary functions data being fed back to set the component tolerances
or shapes apart from fulfilling the most function during detailed design. Simultaneously, engineers have
(economic realization) begun using analysis techniques such as Monte Carlo
• Reliable: - the merchandise is usable in an analysis to predict the distribution of the design
exceedingly myriad of conditions without harming performance, rather than simply accepting or rejecting
the user or environment (safety for both humans the design based on worst case scenarios. Using these
and environment) techniques, engineers can correctly recognize, specify,
Current systems use simplistic approximations of and control those few tolerances that dominate the
production tool interval and production rate, which design performance,thereby leading to improved
rely on the manufacturing facility. the subsequent product performance at lower cost.
generation of systems will must incorporate these In addition to FMEA, CAD/CAM software is an
parameters during a better way. Furthermore, current important DFM tool for detailed design that utilizes
systems use only manufacturing costs in performing CAD software to describe part geometries to, for
process and material selection. Because life cycle costs example, define toolpaths to direct the motion of a
have a serious role within the decision, they must be machine tool to form the part. Today, most new
considered within the next generation of systems. machine tools incorporate CAM and Numerically
Controlled (NC) technologies. To further facilitate DFM,
3.4 DFM in detail design CAD/CAM systems can be integrated with process
planning and other technologies such as Group
Given the selection of materials and processes during Technology (GT) and Cellular Manufacturing. Finally,
embodiment design and facing the impending release Flexible Manufacturing Systems (FMS) and Just-In-
of the product design to manufacturing, a host of DFM Time Production (JIT) are important concepts made
techniques are frequently applied in an effort to possible by CAD/CAM systems, affecting the
identify issues, catch mistakes, and avoid downstream integration of manufacturing cells, productivity and
changes. During detailed design, integration with quality in a wide variety of strategic industries (e.g.,
Computer Aided Design (CAD) tools becomes critical to http://www.gsd.harvard.edu/inside/computer_resour
product and process analysis. For example, integration ces/manual/cadcam/whatis.htm).
of Failure Modes and Effects Analysis (FMEA) and No matter the stage in the design process, DFM is
Computer Aided Manufacturing (CAM) into CAD is recognized as an important component of product
common. development. As such, practice and theory have
Detail design is concerned with both the shape and developed within very specific areas of DFM including
tolerance of a part. Applying DFM to shape is highly Design for Quality, Design for Production, Design for
process-dependent and can be accomplished through Life Cycle Cost, and Design for Environment, as
design standards or expert systems. More generic to all described below.
processes is the consideration of tolerance and its
effect on function. 3.5 DFA in detail design
Specifically, FMEA is a DFM method used during
detailed design that became so prevalent that it is now DFA (Design for Assembly) is a DFM specialty; it is a
a military specification, MIL-STD-1629. In FMEA, the structured method to improve product components
development team systematically evaluates and assembling. Both, DFM and DFA are essentials
documents each failure mode, as well as the failure applications during product design and are also called
mode’s potential impact on system performance, DFMA (Design for Manufacturing and Assembly). The
safety, and maintenance. Each failure mode is then following criteria are considered in a DFA study:
ranked by the severity of its effect in order that
appropriate corrective actions may be taken to
• Reduce and optimize part counts and types.
eliminate or control the high-risk items. Subsequently,
• Utilize optimum attachment methods.
further detailed, embodiment, or even concept design
may be required to address the revealed shortcomings. • Use layered assembly approach. Let gravity help.
Current research (Chao and Ishii, 2003) is striving to • Minimize reorientations during assembly.
lower the burden of conducting FMEA through • Eliminate the need for adjustments.
automation with wizards while extending and • Design parts so that they are easy to self-align and
validating its usefulness. FMEA can address locate.
manufacturing operations to identify ways in which the • Ensure adequate access and unrestricted vision.
product design leads to manufacturing problems. • Ensure ease and safety of part and assembly
The analysis of tolerances and tolerance stack-up handling.
remains important. Previously, industry standards • Design parts that can only be installed correctly.
were blindly accepted as limits on product design and • Minimize the number of tools required.
512| International Journal of Current Engineering and Technology, Vol.11, No.4 (Sept/Oct 2021)
Varsha Karandikar et al Design for manufacturing and Assembly practices in early stage of product development

3.6 Future of DFMA Software • Minimize the number of (different) parts in a

product,
Considerable research and development in the area of • Use standard available components,
product design for manufacture and DFMA has been • Design parts that can be used in multiple product
carried out in the past 25 years. The underlying lines,
philosophy of this work is the early design decisions on • Design components that are simple to produce,
product configurations, together with the selections of • Minimize the number of flexible components,
materials and processes, lock in a large proportion of • Design components that are multifunctional in a
the subsequent manufacturing costs. The DFMA product,
software is a combination of two complementary tools, • Design parts that cannot be assembled incorrectly,
DFM and DFA. The DFM cost program uses an • Maximize symmetry of parts or design them
extensive materials database that includes the deliberately asymmetrical,
materials related parameter for each process. This • Ensure that parts align themselves for assembly,
database also includes processing limits data that aid • Design products that fit in standard packaging,
material and process selection by indicating • Design the product modular.
combination suitability for a given part (Olga Battaïa,
Alexandre Dolgui, 2019) 5. Case Studies
The DFMA software offers a huge savings in time
and money. It will assist in the decision-making Below selective case studies show the actual issues
process for a product design. Another interesting point, identified in an agricultural equipment manufacturing
the user can generate several design options to do company.
some comparison. This software also has one of the DFMA was done on new product in very early phase
most extensive libraries for product’s materials, and all modules were analyzed in detail using DFMA
production processes, fasteners and additional guidelines. The critical cases were shared with product
production operations. engineers and solutions were developed and
John Deere Selects DFMA Software from Boothroyd implemented in design before the actual build of the
Dewhurst, this could enable Deere to reduce the cost of product.
purchased parts in the company's major equipment This exercise helped to avoid the rework which could
divisions. John Deere is the world's premiere producer have occurred during actual assembly and in terms
of agricultural equipment and the world leader in reduce the project milestone timeline.
forestry equipment, as well as major supplier of
construction and lawn and turf care equipment. DFMA 4.1 Case Study 1: Design for Ergonomic assembly
software is a combination of two complementary tools:
Design for Assembly (DFA) and Design for Manufacture In below (Fig 4) situation the part is being held by one
(DFM). Engineers use DFA software to reduce the hand and placing in a fastener with the other hand.
assembly cost of a product by consolidating parts into Weight of the part is more than 8 kg and the assembly
elegant and multifunctional designs. DFM software lone runs with high volume per shift.
then allows the design engineer to quickly judge the Parts under 10 Kg could still pose an ergonomic
cost of producing the new design and to compare it concern when they must be manually positioned and
with the cost of producing the original assembly. An held in place to install. This can become an ergo issue
extensive library in the software enables product over time.
developers to investigate alternative materials and
processes for producing parts and helps them select
Problem
the most cost-efficient design. The cost management Manually
group at John Deere works with cross-disciplinary positioned to
teams that include members of the supply chain. The align holes
teams review a bill of materials for a part to establish a
benchmark. They then perform DFM analyses of
materials and manufacturing processes to re-design
the part and provide the supplier with a should-cost
estimate based on the new design.

4. DFMA and different stages of concurrent

engineering
Before
General guidelines for successful implementation of
DFMA varies per organization, industry and product.
However, the followings are guidelines generally
provided to cost optimization (F.Z. Krumenauer, C.T.
Matayoshi, I.B. da Silva, M.S. Filho, G.F. Batalha, 2008.) Fig. 4 Product design before DFMA
513| International Journal of Current Engineering and Technology, Vol.11, No.4 (Sept/Oct 2021)
Varsha Karandikar et al Design for manufacturing and Assembly practices in early stage of product development

Solution after DFMA:In (Fig.5) Adding a simple lip to restriction for assembly and tightening the nut with
support the weight of the part and align holes for wrench and has got clear visibility.
assembly resolves issue.
The extra lip provided hold the part and bear the
weight, so operator now can easily assemble the
hardware without much efforts for lifting the part.

Fig. 7 Product design after DFMA

4.3 Case study 3 - Design to Largest Functional

Tolerance Compatible w/Factory Capability

After In (Fig.8) A two bolt bracket is secured to another part.

Parts must bolt together at extreme limits of tolerance.

Fig. 5 Product design after DFMA

4.2 Case Study 2: Design for Tool & Operator

Accessibility

In (Fig 6), part is assembled on the C channel using

spacer along with bolt and nut. And then nut is
tightened with wrench.
In this assembly, operator has very limited space to
assemble the nut and don’t have much visibility. Also,
Wrench don’t get the required 60 degree of span to
tighten the nut due to restricted access

Fig. 8 Product design before DFMA

Solution after DFMA:(In Fig 9) Hole alignment can be

assured using tight tolerances and geometric
positioning, but may dictate a more expensive process,
such as drilling. Designing the part with a hole and a
slot allows part to be held in same position as 2-hole
design, but made with a less expensive process, such as
stamping.

Fig. 6 Product design before DFMA

Solution after DFMA: In (Fig.7) Design is changed and

assembly will be done from top to down. In this case
part count is also reduced and Operator has no Fig. 9 Product design after DFMA
514| International Journal of Current Engineering and Technology, Vol.11, No.4 (Sept/Oct 2021)
Varsha Karandikar et al Design for manufacturing and Assembly practices in early stage of product development

4.5 Case Study 4: Design for Parts Orientation and DFMA is a good method to optimize a design for mass
Handling production at an early stage, so that the product can be
efficiently and effectively be produced and assembled.
In (Fig.10) – before here Hole alignment is major Also, for an existing product it may be worth to carry
problem. The part is bolted to frame after placing it on out a DFMA study to reduce costs and improve quality.
the frame. DFMA tools are useful in reducing the time taken to
Part weight make holes difficult to align and cannot evaluate designs and therefore it should be
be assembled in target cycle time implemented as part of the design selection process.
With the help of case studies, it is revealed that how
DFMA beneficial for identifying the issues in product
design and product manufacturing if we apply it in
early stage of product development and also it can
enhance ergonomic conditions of operator and reduce
product launch time.

References
Tab formed on
part seats in
slot on Frame Poli C (2001) Design for manufacturing: a structured
approach. Butterworth-Heinemann, UK
Swift KG, Brown NJ (2003) Implementation strategies for
DFM. P I Mech Eng B J Eng 217:827–833
Lovatt AM, Shercliff HR (1998) Manufacturing process
selection in engineering design. Part 2: The role of
process modelling. Mater Des 19:217–230
0Boothroyd G, Dewhurst P, Knight W (2001) Product
design for manufacture and assembly, 2nd edn. Marcel
Fig. 10. Product design before DFMA Dekker, New York
Swift KG, Booker JD (2003) Process selection: From
In (Fig. 11) – Self aligning feature is added in the design to manufacture, 2nd edn. Butterworth-
design. Locating” tab added to part from existing Heinemann, UK
material Ashby MF, Brechet Y, Cebon D, Salvo L (2004) Selection
Tab assembles in slot in frame and aligns all strategies for materials and processes. Mater Des
mounting bolt holes 25:51–67
Part can easily be assembled under target cycle Esawi AMK, Ashby MF (2003) Cost estimates to guide
time preselection of processes. Mater Des 24:605–616
Edwards KL (2003) Designing of engineering components
for optimal materials and manufacturing process
utilization. Mater Des 24:355–366
“DFM Conceptual Design Review “Report, Editor: Michele
Modena, EDMS 2175578ver. 1.0, 5July2019
Tab formed on Pahl G. et al. 2007, “Engineering design; a systematic
part seats in
slot on Frame
Approach,” Germany, 3rd ed.
Kesselring F., 1954, “Technical composition,” springer,
Berlin.
Dieter, G.E., 1991 “Engineering Design,” McGraw-Hill, New
York
MS Hundal. 1997, “Systematic Mechanical Designing: A
Cost and Management Perspective”, NewYork.
Fig. 11 Product design after DFMA F.Z. Krumenauer, C.T. Matayoshi, I.B. da Silva, M.S. Filho,
G.F. Batalha, 2008,“Concurrent engineering and DFMA
Conclusions approaches on the development of automotive panels
and doors,
This Research paper presents the scope of DFM tools TIMÁR, Imre, Tibor BORBÉLY, István LISZTES, and Pál
which has expanded in many ways: to applications for HORVÁTH. "Cost calculations with method of design for
different phases of design, to manufacturing system manufacture and assembly (DFMA)." Annals of the
performance, to platform design and system quality, Oradea University, Fascicle of Management and
and to life cycle cost and environmental Technological Engineering 9: 4-288, 2010.
considerations. Though this variety is tremendous, Olga Battaïa, Alexandre Dolgui,(2019),”Design for
there are some general guidelines that suggest how manufacturing and assembly/disassembly”, pp 7181-
manufacturing firms can gain from DFM tools. 7189

515| International Journal of Current Engineering and Technology, Vol.11, No.4 (Sept/Oct 2021)