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Customisation in manufacturing: The use of 3D
printing
Rengarajan Srinivasan, Vaggelis Giannikas, Duncan McFarlane and Mudassar
Ahmed
Distributed Information and Automation Laboratory, Institute for Manufacturing, Universi-
ty of Cambridge, 17 Charles Babbage Road, United Kingdom
{rs538, v.giannikas, dcm, ma603}@eng.cam.ac.uk
Abstract1. An increasing demand to provide customised products creates
challenges for manufacturing organisations. This poses a need to understand
the characteristics required for manufacturing systems to handle customisa-
tion. In this study, 3D printing technology is assessed as an enabler for cus-
tomisation. Additionally, the requirements of manufacturing systems with
respect to configuration and control co-ordination are explored. A demon-
strator is implemented to integrate 3D printing with conventional manufac-
turing, using an agent based distributed control system that co-ordinates the
customisation of products and the order management.
1 Introduction
Dynamic changes in customer requirements and preferences are driving the needs
for highly customised products [1]. This customer-oriented focus allows organisa-
tions to stay competitive in the global market and to satisfy varying customer de-
mands. This requires manufacturers to deliver high variety of products, individual-
ly designed at a low cost [2]. Nevertheless, the need for a high degree of
customisation creates disruptions in the manufacturing system and poses problems
in scheduling. As a result, manufacturing systems are required to be flexible and
resilient to disruptions [7]. Additionally, customisation leads to small batch sizes
and requires frequent and dynamic re-configuration of the manufacturing system.
This creates additional burden on the control system to dynamically alter process
1 This is a machine-readable rendering of a working paper draft that led to a publication. The publica-
tion should always be cited in preference to this draft using the following reference:
• Srinivasan, R., Giannikas, V., McFarlane, D., Ahmed, M.: Customisation in manufacturing: The case
of 3D printing in Proceedings of the 6th Workshop on Service Orientation in Holonic and Multi-
Agent Manufacturing, Lisbon, Portugal (2016).
This material is presented to ensure timely dissemination of scholarly and technical work. Copyright
and all rights therein are retained by authors or by other copyright holders. All persons copying this in-
formation are expected to adhere to the terms and constraints invoked by each author’s copyright. In
most cases, these works may not be reposted without the explicit permission of the copyright holder.
2
steps and change tools, routing and material handling. Therefore, a manufacturing
system should be able to handle rapid changes and product variety utilising flexi-
ble resources and intelligent control.
In this paper, the ability of 3D-printing as an enabler to handle customisation is
explored. The configurations to integrate 3D printing technology with convention-
al manufacturing systems are proposed. A distributed agent based control system
is implemented in a laboratory system to demonstrate the applicability of 3D print-
ing in handling customisation in a conventional manufacturing system.
2 Manufacturing systems supporting mass customization
Mass customisation can be defined as the ability to deliver a wide range of prod-
ucts that meet specific requirements of individual customers, at a cost equivalent
to mass production [1, 2]. Generally, the ability to provide mass customisation re-
quires manufacturers to have flexible resources that can handle product variety
and have the ability to change over quickly. In this section we review such re-
quirements and we argue on the suitability of 3D printing to support mass custom-
isation.
2.1 Handling customisation in manufacturing
In order to handle the issues related to customisation, the following characteristics
of the manufacturing system are required [1, 2, 5]:
R1 – Customer driven manufacturing: The customer needs to be involved in the
specification, design and manufacture of the customised parts. Generally, two op-
tions exist here. Firstly, the customer can specify the requirements and preferences
of the product and the manufacturer focuses on design and production. Alterna-
tively, the customer can himself design the product or parts and provide the design
to the manufacturer to produce the product. In both instances, the manufacturing
system should have the ability to handle this.
R2 – Integration of design and manufacturing systems: Involvement of customers
in the design process requires seamless integration of design and manufacturing
systems to quickly transition from design to manufacture. The decoupling point of
order, the point where customer influences the manufacturing process, varies de-
pending on the level of customisation or customerisation offered. This requires
better integration of Computer Aided Design (CAD) and Computer Integrated
Manufacturing (CIM), which will allow in ease of customised manufacturing.
R3 – Flexibility: The manufacturing system should be flexible enough to make a
wide range of product variations and the resources should have multiple capabili-
ties to handle this. Furthermore, the manufacturing system should have pro-
cess/material flow flexibility to handle various customisation aspects.
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R4 – Management of inventory of great variety: High degree of customisation cre-
ates a wide range of product variety and this leads to increasing levels of inventory
to tackle the uncertainty with regards to customer preferences. Therefore, the
manufacturing systems should have the ability to minimize inventory levels whilst
handling customisation requests.
R5 –Management of customised orders: Customisation leads to varying order due-
dates and reduced batch sizes. Additionally, the customer orders might arrive at
random times. This requires the manufacturing system to have the ability to man-
age the orders by rescheduling dynamically and to have the capability to handle
rush orders.
In order to address these requirements, the following are needed:
• Flexible resources with capability to make or handle customised parts
• Manufacturing system configuration able to utilise the flexible resources
• Control system for co-ordinating customised orders and flexible resources
In this paper, 3D printers enabling rapid, additive manufacturing are evaluated
as an example of a flexible resource for handling customisation issues. This is dis-
cussed more in the following section. Subsequently, we discuss the configuration
and co-ordination issue in the section that follows.
2.2 3D printing technology enabling mass customisation
In this section, the suitability of rapid manufacturing, especially 3D printing tech-
nology, for the management of customisation disruptions is assessed. Rapid manu-
facturing is defined as the use of CAD-based automated additive manufacturing
process for making parts that can be used as a finished product or as a component
that can be assembled into a final product [6]. 3D printing technology is a form of
an additive manufacturing process, where products are produced by adding layers
of materials [3].
With regards to the first requirement (R1) the ability of 3D printing machines to
directly utilise 3D models of designed products allows the customer to design his
preferences related to products directly [4]. Additionally, the customers can co-
design products or choose the design by other customers in a marketplace. This al-
lows for high degree of customisation. Additionally, 3D laser scanners can be used
to map the products to get a digital design of the product directly, which enable
the customers to design customisation aspects directly. Furthermore, the 3D de-
sign models from the customers can be directly transferred to the 3D printer for
manufacturing.
The integration of design and manufacturing system requirement (R2) is ad-
dressed by 3D printing as CAD drawings can be directly imported or converted in-
to appropriate instructions for additive manufacturing automatically. This allows
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quick transition from design to manufacture and provides rapid customisation ca-
pabilities.
As regards flexibility (R3), 3D printing based manufacturing removes the tool-
ing requirements and thereby allows components of any geometry to be manufac-
tured in a single resource without too much change over time [4, 8]. 3D printing
eliminates the need for having a wide range of tooling and the associated costs.
Furthermore, multiple materials can be combined to produce a part, rather than
products or parts made of homogeneous materials. Additionally, 3D printing al-
lows for small batch sizes and there is no change over of tools, thus providing
flexibility to cater for various customisation requests. Similarly, 3D printing based
manufacturing offers the possibility of reducing inventory levels of customised
parts as some of them can be produced on demand based on actual customer or-
ders (R4).
2.3 Configurations and co-ordination for 3D printing-based customisation
There are a number of different configurations that allow the usage of 3D printers
in manufacturing depending upon the level of customisation required. These dif-
ferent configurations will require different co-ordination capabilities to control
and manage customisation requests. Three possible configurations are depicted in
Figure 1.
Fig. 1: Configurations for the usage of 3D printing in manufacturing
The first configuration illustrated in Fig. 1 allows 3D printed parts and compo-
nents produced by printers belonging to different organisations to be used in the
production of a product. These 3D printed parts are manufactured in different ge-
ographical locations and need to be transported to the location of the main manu-
facturer of a product for final assembly. The co-ordination needed in this case re-
fers to the assignment of a printing job to external organisations and to the
physical transportation of a part in a manufacturing line.
The second configuration describes the case where the conventional manufac-
turing line and the 3D printer belong to the same company. Here, conventional
and flexible resources are located in the same geographical area and they are man-
aged by the same company. However, the 3D printer is used only for making cus-
tomised parts. The co-ordination aspects in this configuration are similar to the
Conventional
Manufacturing
3rd Party/External
3D printer
Conventional
Manufacturing
Stand-alone 3D
printer
Conventional
Manufacturing +
Integrated 3D printer
A: Inter-organisational configuration
Assembly
process
Assembly
process
B: Intra-organisational configuration C: Integrated configuration
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ones of the first configuration although the manufacturer will have greater control
over both processes.
The third configuration depicts an integrated approach where 3D printers are
part of a production line along with other resources (e.g. robots) and tools. It illus-
trates the case where 3D printers have seamlessly been integrated in existing man-
ufacturing processes and are considered part of the overall manufacturing system.
In this configuration, the 3D printer is also involved in the making of conventional
parts as part of the manufacturing system. One of the main issues here is introduc-
ing 3D printing resources in existing systems and controlling them along with oth-
er manufacturing resources.
In order to examine the introduction of 3D printing in conventional manufactur-
ing in more detail, a demonstrator was developed. The demonstrator uses the intra-
organisational configuration as a configuration that allows a manufacturer to use
3D printing without the need to outsource to external parties (inter-organisational
configuration) and without the need for significant changes in the existing manu-
facturing line (integrated configuration). This demonstrator is described next.
3 Demonstrator
In this section, we describe the developed demonstrator as well as our key findings
in terms of meeting the customisation requirements discussed in Section 2.
3.1 Set-up
The production system used in the demonstrator produces a gearbox (Fig. 2) con-
sisting of: i) a metal casing made of two parts, top and base, ii) a plastic top cover,
iii) gears which go into the casing (metal or customisable plastic), iv) (optional)
customisable cap. The customers have two options for customisation. First, the
customer can have a choice of different coloured gears with different gear ratios.
Additionally, the customers can prefer to have a custom made cap for the gearbox
with added text.
The production system for manufacturing the gear box consists of three cells.
Cell 1 is a manufacturing cell, where the metal casing is machined by a 5-axis
CNC machine and the plastic part is formed by a vacuum forming machine. Cell 2
is the sub-assembly process where the metal top and the plastic cover are aggre-
gated. Cell 3 is the final assembly cell associated with gear meshing and fastening
operations. The customised parts (i.e. gears and cap) are printed and delivered in
Cell 3 by a standalone 3D printer.
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Fig. 2: Gear box
3.2 Implementation
This section illustrates how the three key essential features required for handling
customisation, discussed previously are implemented.
Firstly, a 3D printer is used as the flexible resource to make the customised
parts (i.e. gears and caps), which delivered to Cell 3 and are integrated into the fi-
nal product. The use of 3D printing allows easy transition from design to manufac-
ture and offers additional flexibility by removing the change-over time between
products. Furthermore, the use of 3D printers eliminates the need to have custom-
ised parts being maintained as inventory.
With regards to configuration, Figure 3 shows the configuration implemented
in the demonstrator. The 3D printer is implemented as a stand-alone resource that
is dedicated to making customised parts only (i.e. intra-organisational configura-
tion). Cell 1 and cell 2 are conventional manufacturing systems which deliver the
metal base and the sub-assembly (metal top and plastic cover) to Cell 3. The 3D
printer delivers customized parts to cell 3 to be integrated into final assembly.
Metal or
customisable
plastic gears
Customisable
cap
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For co-ordination between the conventional manufacturing and the 3D printer,
a distributed control system was implemented. The distributed control was based
on multi-agent systems and was implemented using the JADE framework (see fig.
3). The agents and their roles in co-ordination are:
• Order agent: Responsible for negotiating the task allocation with the various
manufacturing resources. Additionally, the orders will have the customisation
requests associated with a design file. The order agent then negotiates and re-
serves the job with the 3D printer.
• Customisation agent: This agent represents the 3D printer and is responsible for
managing customisation request and for scheduling the printing operations
based on order due dates.
• Resource agents: These agents represent the typical manufacturing resources
such as CNC machine and robots for material handling. These agents are re-
sponsible for managing task allocation and order management.
The stand-alone 3D printer is implemented as an intelligent resource capable of
making its own decision with respect to customisation and scheduling. This is en-
abled by having a Raspberry Pi computer integrated with the 3D printer. The inte-
grated computer then has the capability to receive and process messages from the
orders, and also control the additive manufacturing process.
Fig. 3: Demonstrator configuration and control
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3.3 Meeting customisation requirements
We conclude this section with a discussion on the way the five customisation re-
quirements identified in Section 2 have been met in our demonstrator. These are
summarised in Table 1.
Table 1. Customisation requirements implemented in demonstrator
Requirements
Implementation
Customer
driven manu-
facturing
The customers can decide the choice of options for the gears
and ratios, along with the optional customised caps. The man-
ufacturer has the required design in CAD which is then trans-
ferred to the 3D printer for printing.
Integration of
design and
manufacturing
systems
3D printer is directly linked to the manufacturing system. Or-
ders are associated with the required design information and
are transferred directly to the 3D printer, which converts the
design into appropriate commands for printing the parts.
Flexibility
3D printer can print both customised gears and caps from the
same resource, thereby offering flexibility to use a single re-
source for all customisation needs.
Management
of inventory of
great variety
The ability to make parts quickly and on request eliminates
the need to hold inventory. Additionally, the customised parts
can be produced from a single material, thereby reducing the
complexity and level of inventory needed.
Management
of customised
orders
Intelligent orders and resources having distributed decision
making ability allow the orders to negotiate and schedule tasks
independently. This provides flexibility to handle small batch
sizes and re-schedule dynamically to cater for rush orders on
customisation.
4 Conclusions
In this paper we investigated the suitability of 3D printing to handle customisation
needs. 3D printing was chosen as a technology providing flexible and rapid manu-
facturing capabilities. Our analysis shows that the technology can indeed be used
for enhancing the customization capabilities of conventional manufacturing sys-
tems. Nevertheless, the integration of 3D printing with conventional manufactur-
ing systems poses challenges in:
• Automation: Lacks ability to automatically transfer materials in and out of the
3D printer. In-process sensing of product quality is not well developed.
• Communication: Existing 3D printers have different communication interfaces
(e.g Ethernet, serial port) and are not inter-operable with standard manufactur-
ing devices (e.g. PLC).
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• Interfaces: There is limited control interfaces to monitor and execute tasks in
3D printers. Ability to control and communicate with 3D printers varies be-
tween manufacturers (open source vs proprietary tools). Furthermore, the con-
version of CAD files into machine codes are not standardized.
5 References
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