**2.1 Welding operation in rail car assembly**

Welding is one of the methods usually employed for joining the components parts during rail car development. It is a complex manufacturing process, which requires the combination of a number of different factors such as material metallurgy, process parameters, welding sequence, power source, energy, speed, filler materials as well as the material combination and thickness for the design of an efficient process. Hence, an optimised welding process will bring about the development of reliable weld joints and shorter welding cycles via efficient process development.

**157**

*Application of the Fourth Industrial Revolution for High Volume Production in the Rail Car…*

tioned processes depending on the design and performance requirements.

A robot is a reprogrammable, multifunctional manipulator designed to move materials, parts, tools, or specialised devices, to variable programmed motions for the performance of a variety of tasks [17]. Robotic solutions for the assembly, maintenance and repair applications in the rail car and transit coaches is essential for performing activities such as welding, grinding, cleaning, and painting due to increasing complexities, repetitive, and high volume production requirement. Other advantages of the use of robots for assembly operations include; automation via less human involvement, increased precision and productivity, consistent weld penetration resulting in better quality and surface finish, safety, improved product quality, reduction in assembly interruptions, flexibility and reduced labour costs. This work proposes a dual arm, 12-axis welding robot with advance sensors, camera and algorithm as well as intelligent control system. It also has robotic manipulator with an end-effector for gripping, positioning and welding of various component parts during rail car manufacturing. The smart sensors, which are the basic building blocks of the Internet of Things (IoT), are incorporated for data collection to enhance the process condition and real time monitoring, diagnosis and efficient communication. A large amount of data gathered through the smart sensors and IoT for are often suitable for the analysis and development of predictive algorithm. The automation of the welding process via effective communication and intelligent coordination will improve the overall efficiency and safety of the assembly process. This will decrease the failure rate, interruptions, and enhance the reliability of manufacturing and maintenance activities. The dual arm is to allow multiple task to be carried out in order to reduce the assembly time with increase in the production rate while the sensors and intelligent control system are to monitor and provide necessary feedbacks relating to weld imperfections and quality. This will lead to significant reduction in the welding cycle time with higher deposition rate and consistent weld penetration. Since the overall production cost is partly a function of the welding cycle time and the production rates, the use of the dual arm-welding robot will bring about significant reduction in the overall production cost. Another advantage is that there will be significant reduction in the welding error and expensive rework due to less human involvement, leading to the production of assembly that meets design and customer's requirements. In addition, the choice of automated dual arm robot will sufficient address the issue of monotonous repetitive task as well as other safety and ergonomic issues relating to assembly operations in complex geometries as opposed to manual assembly lines. Depending on the type of

The welding operation is usually employed for the assembly operations in the underframe, body side, side panel, bogie frame and roof among others. The underframe, which is the part of the body shell, has parts, which includes the bars, runners, bolsters etc. The upper and lower brackets are usually welded on to the underframe through arc welding while the friction stir welding (FSW), resistance spot welding (RSW), metal inert gas (MIG) or laser arc welding (LAW) are usually employed for joining the body side. The body sides are made from high strength stainless steel or light aluminium materials that are welded on a frame. The body shells are first welded before the fitting operations and the windows are either cut out of the body side panels or the sides assembled in sections through the pre-installed window frames. Furthermore, the side panel are welded on to the frame of the body side. The welding process is also employed in the joining of the roof with specialised contourshaped jigs, which holds the roof for welding operations, and ceiling installations. The bogie frame is also fabricated via welding operation before the assembly of the suspension systems. Different welding methods are employed for all the aforemen-

*DOI: http://dx.doi.org/10.5772/intechopen.88703*

**2.2 Robotic solution for mass production**

#### **Figure 2.** *The framework for rail car development and supply chain activities.*

*Application of the Fourth Industrial Revolution for High Volume Production in the Rail Car… DOI: http://dx.doi.org/10.5772/intechopen.88703*

The welding operation is usually employed for the assembly operations in the underframe, body side, side panel, bogie frame and roof among others. The underframe, which is the part of the body shell, has parts, which includes the bars, runners, bolsters etc. The upper and lower brackets are usually welded on to the underframe through arc welding while the friction stir welding (FSW), resistance spot welding (RSW), metal inert gas (MIG) or laser arc welding (LAW) are usually employed for joining the body side. The body sides are made from high strength stainless steel or light aluminium materials that are welded on a frame. The body shells are first welded before the fitting operations and the windows are either cut out of the body side panels or the sides assembled in sections through the pre-installed window frames. Furthermore, the side panel are welded on to the frame of the body side. The welding process is also employed in the joining of the roof with specialised contourshaped jigs, which holds the roof for welding operations, and ceiling installations. The bogie frame is also fabricated via welding operation before the assembly of the suspension systems. Different welding methods are employed for all the aforementioned processes depending on the design and performance requirements.

### **2.2 Robotic solution for mass production**

*Mass Production Processes*

bolsters, runners, bars etc.

body side, underframe, roof, body shell etc.

**2.1 Welding operation in rail car assembly**

e. System: Rail car, rolling stock, rail track, control unit

b.Component parts: Compressor, brake parts, blower, cable, controls, indicators, rectifiers, inverters, carbon fibre etc. gears, sensors, printed circuit boards,

c.Sub assembly: Mechanical: Wheelset, suspension system, bogie, brake, engine,

d.Electrical/electronic: Communication, security, power, integrated software etc.

In order to maximise the benefits of the advanced manufacturing technologies, the perceived industrial key players can develop the theory driving the elements of the new industrial revolution into practical knowledge as stated in the following subsections.

Welding is one of the methods usually employed for joining the components parts during rail car development. It is a complex manufacturing process, which requires the combination of a number of different factors such as material metallurgy, process parameters, welding sequence, power source, energy, speed, filler materials as well as the material combination and thickness for the design of an efficient process. Hence, an optimised welding process will bring about the development of reliable weld joints and shorter welding cycles via efficient process development.

**156**

**Figure 2.**

*The framework for rail car development and supply chain activities.*

A robot is a reprogrammable, multifunctional manipulator designed to move materials, parts, tools, or specialised devices, to variable programmed motions for the performance of a variety of tasks [17]. Robotic solutions for the assembly, maintenance and repair applications in the rail car and transit coaches is essential for performing activities such as welding, grinding, cleaning, and painting due to increasing complexities, repetitive, and high volume production requirement. Other advantages of the use of robots for assembly operations include; automation via less human involvement, increased precision and productivity, consistent weld penetration resulting in better quality and surface finish, safety, improved product quality, reduction in assembly interruptions, flexibility and reduced labour costs. This work proposes a dual arm, 12-axis welding robot with advance sensors, camera and algorithm as well as intelligent control system. It also has robotic manipulator with an end-effector for gripping, positioning and welding of various component parts during rail car manufacturing. The smart sensors, which are the basic building blocks of the Internet of Things (IoT), are incorporated for data collection to enhance the process condition and real time monitoring, diagnosis and efficient communication. A large amount of data gathered through the smart sensors and IoT for are often suitable for the analysis and development of predictive algorithm. The automation of the welding process via effective communication and intelligent coordination will improve the overall efficiency and safety of the assembly process. This will decrease the failure rate, interruptions, and enhance the reliability of manufacturing and maintenance activities. The dual arm is to allow multiple task to be carried out in order to reduce the assembly time with increase in the production rate while the sensors and intelligent control system are to monitor and provide necessary feedbacks relating to weld imperfections and quality. This will lead to significant reduction in the welding cycle time with higher deposition rate and consistent weld penetration. Since the overall production cost is partly a function of the welding cycle time and the production rates, the use of the dual arm-welding robot will bring about significant reduction in the overall production cost. Another advantage is that there will be significant reduction in the welding error and expensive rework due to less human involvement, leading to the production of assembly that meets design and customer's requirements. In addition, the choice of automated dual arm robot will sufficient address the issue of monotonous repetitive task as well as other safety and ergonomic issues relating to assembly operations in complex geometries as opposed to manual assembly lines. Depending on the type of

assembly operations to be performed, the essential factors to be considered for the robotic configurations and selection include the degree of freedom, space geometry, motion characteristics as well as drive and feedback mechanism. In addition, with the process parameters specified and programmed in real time, the robot simply emulate the manual welding process by following a specified or desired trajectory to track the seam geometry and perform the welding operation. This is followed by the post weld assessment with the use of sensors and 3D cameras for the assessment of the weld integrity. The deployment of robotic solutions however is not without challenges. The use of robots for welding requires proper configuration and joint design with consistent gap conditions as variations may lead to time wasting and expensive rework. In addition, robotic welding sometimes is limited by workspace constraints and the need for sensors and intelligent systems for effective monitoring and control. In addition, robots cannot independently make corrective decisions because they are programmed.

**Figure 3** shows the flowchart for the robotic assisted welding.

The design considerations for the robotic arm include the size of the component parts or sub assembly, welding method, welding cycle time, process parameters and repeatability. The robot is designed to move the welding torch along the weld path given the direction of motion and speed as programmed. To control the orientation of the end of the arm, the yaw, pitch and roll axes are added to the other X, Y, and Z axes to make 6 axes for each of the arm.

The specification of the designed dual arm robot is presented in **Table 1**.

For high volume production, the robot can be programmed with set of codes and instructions for the complete welding process and operation following the determination of the weld location, creation of robotic path and setting the process parameters and torch angle. The controller sends signals to the drivers and motors via computer programmes for the execution of the welding operation while the manipulator positions the component parts so that it could be easily accessed and worked upon by the robot. The CAD of the dual arm-welding robot and its exploded are shown in **Figures 4** and **5** respectively.

For increased flexibility and productivity in a mass production setting, the robot is designed such that it can be mounted on a column in order to carry out welding

**159**

**Figure 5.** *The exploded view.*

*Application of the Fourth Industrial Revolution for High Volume Production in the Rail Car…*

**S/N Parameter Value** 1. Reach height 3 m (Max.) 2. Repeatability 0.0001 m (Max.) 3. Velocity 6 m/s (Max.) 4. Weight 400 kg 5. Payload 500 kg 6. Degree of freedom (DoF) 12

operations of complex geometries. In such instance, the work piece is clamped and kept stationary while the robot approaches it for welding operation. This will eliminate the idle as well as loading and unloading time. In order to ensure an efficient performance of the robot, the motion of the robot was simulated using the adaptive neuro-fuzzy interference system (ANFIS) modelling which comprises of a fuzzy system whose parameters are fine-tuned using the neuro adaptive learning (NAL)

*DOI: http://dx.doi.org/10.5772/intechopen.88703*

*The specification of the designed dual arm robot.*

**Table 1.**

**Figure 4.**

*The CAD of the dual arm robot.*

**Figure 3.** *The flowchart for the robotic assisted welding.*

*Application of the Fourth Industrial Revolution for High Volume Production in the Rail Car… DOI: http://dx.doi.org/10.5772/intechopen.88703*


#### **Table 1.**

*Mass Production Processes*

assembly operations to be performed, the essential factors to be considered for the robotic configurations and selection include the degree of freedom, space geometry, motion characteristics as well as drive and feedback mechanism. In addition, with the process parameters specified and programmed in real time, the robot simply emulate the manual welding process by following a specified or desired trajectory to track the seam geometry and perform the welding operation. This is followed by the post weld assessment with the use of sensors and 3D cameras for the assessment of the weld integrity. The deployment of robotic solutions however is not without challenges. The use of robots for welding requires proper configuration and joint design with consistent gap conditions as variations may lead to time wasting and expensive rework. In addition, robotic welding sometimes is limited by workspace constraints and the need for sensors and intelligent systems for effective monitoring and control. In addition, robots cannot independently make corrective decisions because they are programmed.

**Figure 3** shows the flowchart for the robotic assisted welding.

axes to make 6 axes for each of the arm.

exploded are shown in **Figures 4** and **5** respectively.

The design considerations for the robotic arm include the size of the component parts or sub assembly, welding method, welding cycle time, process parameters and repeatability. The robot is designed to move the welding torch along the weld path given the direction of motion and speed as programmed. To control the orientation of the end of the arm, the yaw, pitch and roll axes are added to the other X, Y, and Z

For increased flexibility and productivity in a mass production setting, the robot is designed such that it can be mounted on a column in order to carry out welding

The specification of the designed dual arm robot is presented in **Table 1**. For high volume production, the robot can be programmed with set of codes and instructions for the complete welding process and operation following the determination of the weld location, creation of robotic path and setting the process parameters and torch angle. The controller sends signals to the drivers and motors via computer programmes for the execution of the welding operation while the manipulator positions the component parts so that it could be easily accessed and worked upon by the robot. The CAD of the dual arm-welding robot and its

**158**

**Figure 3.**

*The flowchart for the robotic assisted welding.*

*The specification of the designed dual arm robot.*


**Figure 4.** *The CAD of the dual arm robot.*

**Figure 5.** *The exploded view.*

operations of complex geometries. In such instance, the work piece is clamped and kept stationary while the robot approaches it for welding operation. This will eliminate the idle as well as loading and unloading time. In order to ensure an efficient performance of the robot, the motion of the robot was simulated using the adaptive neuro-fuzzy interference system (ANFIS) modelling which comprises of a fuzzy system whose parameters are fine-tuned using the neuro adaptive learning (NAL)

method. The essence of the modelling and simulation is to determine the kinematic motion of the robotic arm. The understanding of the kinematics will ensure the determination of the motion of robot, angles of the joint and arrangement of location of the tip of the arm at the desired position (**Figure 6**).

The predicted angles of joint for the robot are shown in **Figure 7**. The angle determines the rotation of the robot in the predetermined directions. **Figure 7** indicates that the robot can rotate in both the clockwise and the clockwise directions with various angles corresponding to 0°< ω < 450° which the robot might be required to turn.

Most welding robots function semiautonomously. In order to function optimally most especially during assembly operations such as welding, there is need for the development of specialised jigs and fixtures for easy and accurate location, position and clamping of the component work piece. The production of components in mass depends upon the interchangeability that facilitates easy assembly. Mass production methods require fast and relatively simple method of work positioning for accurate operations. Specialised jigs are devices often employed to hold, support, guide and locate a work piece during manufacturing operations. For components or subassemblies produced in mass, the use of jigs saves machining time by eliminating the task of marking out, repetitive check or work set up, measuring and other set up before machining. With the automatic location of work piece, the assembly operation is carried out with high degree of precision and accuracy. The development of specialised but flexible jigs facilitates mass production with the simultaneous operation of different tools in a single set up thereby reducing the handling time. Hence, the use of assembly robot with specialised jigs will also reduce the overall labour and consequent fatigue as the handling operation and time is simplified and minimised. To a large extent, it saves labour cost and the overall cost of machining. The only limitation is that inaccurate location and clamping by the fixturing elements may cause variations in the dimensions of the work piece resulting in weld imperfections or distortions. However, this challenge can be solved with the use of advance sensor and intelligent systems for weld monitoring and control. The assembly of the rail car body requires the use of jigs to ensure rigid clamping and right position of the work piece during the assembly operations. The jigs are designed for specific purpose after the design of the rail car body and its specifications. Conventional jigs are not flexible enough to permit changes of work piece during machining operations. The rigidity of the conventional fixtures often reduces the volume of production, accuracy of surface finish while also increasing production time and cost. Jigs are reconfigured to provide an effective mix of flexible and dedicated equipment which is expandable and whose functionality and productivity can readily be changed

**161**

time.

tips etc.

**Figure 7.**

*Deduced and predicted angles of joint.*

*Application of the Fourth Industrial Revolution for High Volume Production in the Rail Car…*

when needed [18, 19]. Hence, the design of jigs for assembly operation takes into account the cost, time, safety, flexibility, degree of interchangeability, efficiency, surface finish among other factors. This will permit machining of complex geometries to the desired surface finish. For instance, during welding operations, the expansion of work piece and locator due to heat call for more clearance between the locator and the work piece to facilitate easy unloading. Following the supply of the part lists, which are the standardised elements to be held by a jig during the assembly operation, the sorting of the parts into their respective families, is made based on their differences and similarities. Different part families requires different jig orientation hence the need to sort the parts out into their respective families as parts of the same family can be held with the same jig. For instance, the upper and lower brackets of the rail car consists of hundreds of parts that need to be sorted out into part families, followed by the development of specialised jigs for each family

The cost analysis of the robotic welding considers the following; the total welding time, weld size, arc on time, deposition rate of the weld and the labour cost. The total welding time is the sum of the total arc time and the non-arc time as expressed by Eq. 1. While the arc time is the time spent by the robot during the welding operation, the non-arc time is the time spent on other activities such as set up (loading and unloading), inspection, changing wire, shielding gas or contact

*Tt* is the total welding time (s); *At* is the total arc time (s) and *Nt* is the non-arc

*Tt* = *At* + *Nt* (1)

before they are welded on to the underframe through arc welding.

*DOI: http://dx.doi.org/10.5772/intechopen.88703*

**Figure 6.** *Kinematic motion of the robotic arm.*

*Application of the Fourth Industrial Revolution for High Volume Production in the Rail Car… DOI: http://dx.doi.org/10.5772/intechopen.88703*

**Figure 7.** *Deduced and predicted angles of joint.*

*Mass Production Processes*

method. The essence of the modelling and simulation is to determine the kinematic motion of the robotic arm. The understanding of the kinematics will ensure the determination of the motion of robot, angles of the joint and arrangement of loca-

The predicted angles of joint for the robot are shown in **Figure 7**. The angle determines the rotation of the robot in the predetermined directions. **Figure 7** indicates that the robot can rotate in both the clockwise and the clockwise directions with various angles corresponding to 0°< ω < 450° which the robot might be required to turn. Most welding robots function semiautonomously. In order to function optimally most especially during assembly operations such as welding, there is need for the development of specialised jigs and fixtures for easy and accurate location, position and clamping of the component work piece. The production of components in mass depends upon the interchangeability that facilitates easy assembly. Mass production methods require fast and relatively simple method of work positioning for accurate operations. Specialised jigs are devices often employed to hold, support, guide and locate a work piece during manufacturing operations. For components or subassemblies produced in mass, the use of jigs saves machining time by eliminating the task of marking out, repetitive check or work set up, measuring and other set up before machining. With the automatic location of work piece, the assembly operation is carried out with high degree of precision and accuracy. The development of specialised but flexible jigs facilitates mass production with the simultaneous operation of different tools in a single set up thereby reducing the handling time. Hence, the use of assembly robot with specialised jigs will also reduce the overall labour and consequent fatigue as the handling operation and time is simplified and minimised. To a large extent, it saves labour cost and the overall cost of machining. The only limitation is that inaccurate location and clamping by the fixturing elements may cause variations in the dimensions of the work piece resulting in weld imperfections or distortions. However, this challenge can be solved with the use of advance sensor and intelligent systems for weld monitoring and control. The assembly of the rail car body requires the use of jigs to ensure rigid clamping and right position of the work piece during the assembly operations. The jigs are designed for specific purpose after the design of the rail car body and its specifications. Conventional jigs are not flexible enough to permit changes of work piece during machining operations. The rigidity of the conventional fixtures often reduces the volume of production, accuracy of surface finish while also increasing production time and cost. Jigs are reconfigured to provide an effective mix of flexible and dedicated equipment which is expandable and whose functionality and productivity can readily be changed

tion of the tip of the arm at the desired position (**Figure 6**).

**160**

**Figure 6.**

*Kinematic motion of the robotic arm.*

when needed [18, 19]. Hence, the design of jigs for assembly operation takes into account the cost, time, safety, flexibility, degree of interchangeability, efficiency, surface finish among other factors. This will permit machining of complex geometries to the desired surface finish. For instance, during welding operations, the expansion of work piece and locator due to heat call for more clearance between the locator and the work piece to facilitate easy unloading. Following the supply of the part lists, which are the standardised elements to be held by a jig during the assembly operation, the sorting of the parts into their respective families, is made based on their differences and similarities. Different part families requires different jig orientation hence the need to sort the parts out into their respective families as parts of the same family can be held with the same jig. For instance, the upper and lower brackets of the rail car consists of hundreds of parts that need to be sorted out into part families, followed by the development of specialised jigs for each family before they are welded on to the underframe through arc welding.

The cost analysis of the robotic welding considers the following; the total welding time, weld size, arc on time, deposition rate of the weld and the labour cost.

The total welding time is the sum of the total arc time and the non-arc time as expressed by Eq. 1. While the arc time is the time spent by the robot during the welding operation, the non-arc time is the time spent on other activities such as set up (loading and unloading), inspection, changing wire, shielding gas or contact tips etc.

$$T\_t = A\_t + N\_t \tag{1}$$

*Tt* is the total welding time (s); *At* is the total arc time (s) and *Nt* is the non-arc time.

The operating factor (*OF*) is expressed by Eq. (2).

$$OF\_{\perp} = \frac{A\_t}{T\_t} \tag{2}$$

#### **2.3 Additive manufacturing in mass production**

The additive manufacturing has opened up new design possibilities that would help meet the challenges relating to manufacturing processes. Manufacturing processes have shown a rapid development in this present day of industrialisation. As such, keeping up with the demands of sustainability, ever changing market dynamics, and environmental pressure, existing processes and practices are being improved and new technologies are being introduced resulting in an enormously expansion to the size and scale of industrial production [20]. Owing to the movement of mass production to developing countries, a rapid attention is paid to low volume innovative production of customised and sustainable products with high added value being observed with evolving manufacturing technologies to stabilise the economies of other domicile producing countries. In the same manner, competing with the ever-changing supply dynamics as a result of globalisation, manufacturing industries sought after new fabrication techniques to prepare themselves with the necessary tools for increased flexibility and economic low volume production. Additive Manufacturing is considered as one such technique of preparing for mass production due to its flexibility in manufacturing.

Additive manufacturing (AM) is defined as "the process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies, such as traditional machining" according to American Society of Testing and Materials [21]. A lot have already been achieved on the way to the widespread application of AM technology. This is not limited to new design freedom, elimination of tools and fixtures, economic low volume production. However, the present and future development in the additive manufacturing industry should be adopted by industries as this new and potentially disruptive technology can be explored to produce high value products and generate new business opportunities [22].

The ability to fabricate several physical models directly from digital data is a key factor to ensuring product development cycle, hence, assisting in the intelligent manufacturing of products. This is in line with Industry 4.0 depicts smart production. Given that AM is an embedded technique in a digitally connected factory, it involves a lot of information and data processing and transmission between the manufacturing parties involved. Much of the information acquired and transmitted will be of great value during production, thereby, enhancing mass production [23].

In traditional means of production such as injection moulding, "tooling costs" are significant, accounting for as much as 93.5% of traditional manufacturing costs, while in AM the only outlay involved is in updating the design files [24]. Instead of economies of scale, AM can create "economies of scope". As there are, fewer costs associated with switching between making different things, adopting the technology makes it easier for companies to bring a range of products to market.

Adopting and modifying the architecture of the framework proposed by Mellor et al. [22] by focusing on technological variables. The technology factors in the production creation process through AM have been categorised into front-end factors comprising data-preparation and applied software, into machine related factors such as raw material supply, maintenance issues, production capacity and surface quality, and into back-end factors that comprise post-processing steps. The technological factors are as depicted in **Figure 8**.

**163**

enlisted in **Figure 9**.

**Figure 9.**

**Figure 8.**

*production*

production are as follow;

*Application of the Fourth Industrial Revolution for High Volume Production in the Rail Car…*

Products suitable for AM production are desired to have one or more of the following characteristics: high degree of customisation, increased design optimised functionality and low volume production. The factors influencing AM implementation for mass production are categorised into technological, operational, organisational and internal/external factors according to Saberi et al. [25]. These are further

*Framework for influencing additive manufacturing implementation for mass production [22, 25].*

The factors influencing additive manufacturing implementation for mass

a.**Technological factors:** Additive manufacturing involves the elimination of tooling and fixturing, design modification for flexibility and function, lower material wastage and inventory etc. Hence, technological considerations are

*2.3.1 Factors influencing additive manufacturing implementation for mass* 

*DOI: http://dx.doi.org/10.5772/intechopen.88703*

*Technology factors in the AM production creation process [22].*

*Application of the Fourth Industrial Revolution for High Volume Production in the Rail Car… DOI: http://dx.doi.org/10.5772/intechopen.88703*

#### **Figure 8.**

*Mass Production Processes*

ness opportunities [22].

production [23].

The operating factor (*OF*) is expressed by Eq. (2).

*At Tt*

The additive manufacturing has opened up new design possibilities that would

Additive manufacturing (AM) is defined as "the process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies, such as traditional machining" according to American Society of Testing and Materials [21]. A lot have already been achieved on the way to the widespread application of AM technology. This is not limited to new design freedom, elimination of tools and fixtures, economic low volume production. However, the present and future development in the additive manufacturing industry should be adopted by industries as this new and potentially disruptive technology can be explored to produce high value products and generate new busi-

The ability to fabricate several physical models directly from digital data is a key factor to ensuring product development cycle, hence, assisting in the intelligent manufacturing of products. This is in line with Industry 4.0 depicts smart production. Given that AM is an embedded technique in a digitally connected factory, it involves a lot of information and data processing and transmission between the manufacturing parties involved. Much of the information acquired and transmitted will be of great value during production, thereby, enhancing mass

In traditional means of production such as injection moulding, "tooling costs" are significant, accounting for as much as 93.5% of traditional manufacturing costs, while in AM the only outlay involved is in updating the design files [24]. Instead of economies of scale, AM can create "economies of scope". As there are, fewer costs associated with switching between making different things, adopting the technol-

Adopting and modifying the architecture of the framework proposed by Mellor

ogy makes it easier for companies to bring a range of products to market.

technological factors are as depicted in **Figure 8**.

et al. [22] by focusing on technological variables. The technology factors in the production creation process through AM have been categorised into front-end factors comprising data-preparation and applied software, into machine related factors such as raw material supply, maintenance issues, production capacity and surface quality, and into back-end factors that comprise post-processing steps. The

help meet the challenges relating to manufacturing processes. Manufacturing processes have shown a rapid development in this present day of industrialisation. As such, keeping up with the demands of sustainability, ever changing market dynamics, and environmental pressure, existing processes and practices are being improved and new technologies are being introduced resulting in an enormously expansion to the size and scale of industrial production [20]. Owing to the movement of mass production to developing countries, a rapid attention is paid to low volume innovative production of customised and sustainable products with high added value being observed with evolving manufacturing technologies to stabilise the economies of other domicile producing countries. In the same manner, competing with the ever-changing supply dynamics as a result of globalisation, manufacturing industries sought after new fabrication techniques to prepare themselves with the necessary tools for increased flexibility and economic low volume production. Additive Manufacturing is considered as one such technique of preparing for

(2)

*OF* = \_

**2.3 Additive manufacturing in mass production**

mass production due to its flexibility in manufacturing.

**162**

*Technology factors in the AM production creation process [22].*

#### **Figure 9.**

*Framework for influencing additive manufacturing implementation for mass production [22, 25].*

Products suitable for AM production are desired to have one or more of the following characteristics: high degree of customisation, increased design optimised functionality and low volume production. The factors influencing AM implementation for mass production are categorised into technological, operational, organisational and internal/external factors according to Saberi et al. [25]. These are further enlisted in **Figure 9**.

### *2.3.1 Factors influencing additive manufacturing implementation for mass production*

The factors influencing additive manufacturing implementation for mass production are as follow;

a.**Technological factors:** Additive manufacturing involves the elimination of tooling and fixturing, design modification for flexibility and function, lower material wastage and inventory etc. Hence, technological considerations are

divided into front-end factors, machine related factors, back end factors and overall process challenges.

