2020, Volume 8, Issue 1, Pages: 207-213  
J. Environ. Treat. Tech.  
ISSN: 2309-1185  
Journal weblink: http://www.jett.dormaj.com  
What is the impact of industry 4.0 to Green Supply  
Chain?  
Ahmad Hidayat Sutawijaya *, Lenny C Nawangsari2  
1
1Doctoral Program, Universitas Mercu Buana, Indonesia  
Magister Management, Universitas Mercu Buana, Indonesia  
2
Received: 29/05/2019  
Accepted: 02/10/2019  
Published: 30/02/2020  
Abstract  
The development of the Industrial Revolution 4.0 brought consequences for increasing high response and demands for transparency  
from the company. The green management concept that is based on the environment helps improve the performance of the  
organization's environment, minimizes waste, costs efficiency and integrates thinking into the supply chain. The purpose of this study  
is to produce a green supply chain management framework and to know the impact of the existence of industry 4.0. This study uses an  
explanatory qualitative approach by collecting data through the stages of interviewing and observing the event organizers. The research  
object was conducted at 2 (two) management event companies in Jakarta, namely Alphabet and New Diamond Putra. The results of  
the research at the two event management companies, illustrate that there was a significant impact on the 4.0 industrial revolution on  
the implementation of green supply chains, especially in event organizers. The impact consists of new transformations directed at  
change and collaboration from green-based suppliers/vendors, smart event management supported by smart operational indicators,  
smart logistics, smart data, smart warehouses, and event decor. Delivery products that are based on creativity and innovation are needed  
by consumers so as to produce sustainable synergy for the company. Technology support, the internet of things and service (IoT) also  
fundamentally changes the outlook for different lives for companies and consumers.  
Keywords: Industry 4.0, Green paradigm, Supply chain, even organization  
1
foreign tourists visiting 2018 experienced a significant  
increase compared to the number of visits in December 2014,  
1
Introduction  
The emergence of Industry 4.0 implies a new paradigm  
2015, until 2017. Now we are soon entering into a stage of the  
that considers most managerial approaches. The impact of  
these changes is of course with the number of companies  
engaged in manufacturing that have switched to using  
automation systems, meaning the role of human labour  
operators and increasing the role of human labour who have  
high competence. There is one thing that stands out most in  
this era of change, namely the world must respond to these  
changes in an integrated and comprehensive way by involving  
all stakeholders, both global political actors, from the  
government sector to the private sector, academics,  
companies, and of course the wider community (Tribunews,  
017). The global economy is currently at the height of major  
changes compared to the emergence of the First, Second and  
Third Industrial Revolution.  
In the tourism sector, there is an increase, this can be seen  
in the table below, in a report released by BPS showing that  
industrial revolution called the Industrial Revolution 4.0. (14).  
Sung (2018) referred to in his article about the McKinsey  
survey of firms that provide a surprising result. The McKinsey  
survey (March 2017) of 300 leading companies in Southeast  
Asia showed that 9 out of 10 respondents believed in the  
effectiveness of Industry 4.0. and almost no one doubts it. The  
challenge for event organizer companies is to prepare supply  
chains that are integrated with technology. The short-term  
challenge in this regard is preparing Supply Chain, Internal and  
external Logistics (Supply Chain and Logistics) supporting the  
Industry 4.0 era, in order to meet the speed of the "demand"  
2
(
Demand). (Ketum ALFI Yukki N Hanafi, 2018). Supply  
chain & Logistics management 4.0 makes technology  
disruption so fast and makes existing companies out of their  
comfort zone.  
Corresponding author: Ahmad Hidayat Sutawijaya, Doctoral Program, Universitas Mercu Buana. Email: ahsuta69@gmail.com.  
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Table 1: Number of Foreign Tourist Visits, 2014-2019  
So that the follow-up is adaptation readiness to new  
technologies, where humans will further optimize the  
functions of strategic intelligence and assisted artificial  
intelligence (Artificial Intelligent/AI), Internet of Thing (IoT)  
to obtain high-scale production and meet increased efficiency.  
Talk about an event organizer, an activity that has a wide range  
and has a very important role, namely helping to realize the  
goals expected by the owner of the fund (commonly referred  
to as a client), starting from the process of creating concepts,  
site preparation, licensing, supporting equipment, artist &  
talent, documentation, up to the course of the event and if  
necessary, the publication of the event in the mass media. In  
the era of industrial revolution 4.0, the role of event organizers  
experienced a shift that was significant in terms of utilization  
and growth of technology that could not be dammed so that the  
service industry such as event organizers experienced  
adjustments in the form of increased effectiveness and  
efficiency.  
However, different views of the revolution 4.0 era  
associated with supply chain management are predicted to  
uproot the work that is often done by humans because it will  
be replaced by a machine. (Business Economics, 2018). That  
is a real challenge with the existence of 4.0 or fourth generation  
supply chain management, thus narrowing employment  
opportunities for humans. Its presence made the disruption of  
technology present so fast and threatened the existence of  
existing companies and had to leave the comfort zone. There  
is a need to revolutionize the company in making things and  
providing services now. In Indonesia, at the end of 2017, there  
were many financial institutions, such as many local banks that  
made reductions in the workforce. This is because they are  
unable to follow or cannot compete with technology. The  
bank's front office workers who previously addressed  
customer problems have now been replaced by ATMs  
(Automated Teller Machines) and mobile banking or internet  
banking. So with the existence of disruptive technology, this  
will make a big change and will gradually turn off traditional  
business.  
The research question in this paper is what is the impact of  
the existence of industry 4.0 on the implementation of green  
supply chain management? The purpose of this paper is to  
produce a green supply chain framework and analyze the  
impact of industry 4.0 so that sustainable corporate goals will  
be achieved.  
2
Literature Review  
2
.1 What is industry 4.0  
The term industrial 4.0 first appeared in 2011 in Hannover,  
Germany. This revolution was created to mark the fourth  
industrial revolution, a new paradigm made possible by the  
introduction of the Internet of Things (IoT) into manufacturing  
and Service environments. Industry 4.0 targets the  
incorporation of information technology with a new era  
industry that is cost-effective, energy-efficient, high-efficiency  
equipment, sharing data through operating systems and  
software that can communicate with each other with internet  
connectivity. The main element of industry 4.0 is the Internet  
of Things (IoT). The presence of Industry 4.0 will provide  
benefits in terms of increasing productivity, efficiency,  
flexibility and a high level of product customization for the  
industrial world.  
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Implementing supply chain management usually begins  
with the manufacturer integrating internal processes. Further,  
the company tries to integrate external suppliers. Finally is  
integrating the external distributors. Green supply chain  
management has focused on the role of the supply chain with  
regard to its impact on the present natural environment as well  
as to the generation of any future environmental change (Reid  
&
Sander, 2011).  
Furthermore, green energy management, reduction of  
greenhouse gas emissions, water conservation or processing,  
waste reduction, reduced packaging / increased use of  
biodegradable packaging, product and packaging procurement  
practices (9, 10). Example of implementing a green supply  
chain is the Samsung Company. In 2007, the Samsung  
Company started the Recycling Direct Program, in which  
Samsung collaborated with suppliers and distributors to pick  
up the remaining electronics. Samsung provides hundreds of  
locations for consumers to submit unused electronic products  
(
Samsung branded goods or non-Samsung ones). This  
program succeeded in recycling 7 million kilograms of used  
electronic goods. Another company that applies the green  
supply chain concept is Hewlett Packard with HP's Supply  
Chain Social and Environmental Responsibility Policy. The  
HP Company is committed to its suppliers around the world to  
care about the environment as a component that feels the  
impact of manufacturing pollution. The initial purpose of  
adopting lean and green types of waste, lean techniques and  
reducing environmental impact through the utilization of green  
practices. Such practices extend beyond the organization to  
include inbound and outbound logistics along with reverse  
logistics (13).  
Figure 1:  
Industry 4.0 requires research stages that are long enough  
to produce mature concepts and concrete results (Roser, 2015).  
The development and progress of technology produce a variety  
of new things, namely:Technology & language. A language  
translator tool, automatically and directly the tool can translate  
from "whatever" to "whatever" language with Voice to Voice  
technology. Technology & transportation. Mr Elon Mus k  
discovered the concept of Hyperloop, this transportation  
moves equal to the speed of sound and faster the average speed  
of an aeroplane. In 2017, in the United States, the Hyperloop  
prototype was successfully created. Technology & exploration  
into the new world. In the coming years, it is estimated that  
humans have been able to fly out of space. This can be  
witnessed how large companies have designed it there, such as  
SpaceX (owned by Elon Musk), Blue Origin (owned by Jeff  
Bezos), and Virgin Galatic (owned by Richard Branson).  
2.3 Even an organization  
Event Organizer is the manager of an activity (Organizing  
Events). Every activity held aims to gain benefits on both  
parties, both the organizers and those present at the event.  
The event organizer is a service intended for the purpose  
of people to organize a well-organized event. In every Event  
Organiser, there must be people who understand the  
organization of events ranging from A to Z. Usually,  
experience and flight hours are high. (2). According to  
2
.2 Green supply chain management  
Green supply chain management is defined as the  
Goldblatt (Goldblatt, 2013): Event Management is a  
coordination of supply chains in a form that integrates  
environmental concerns and considers inter-organizational  
activities. So Green Supply Chain Management (GSCM) aims  
to suppress and minimize environmental damage caused by  
industrial activities, or service companies so that these  
environmental events are translated into supply chain  
management. Green supply chain management focuses on the  
acquisition, production, and distribution to enhance  
profitability, competitiveness, and the resilience of suppliers,  
manufacturing systems, distribution centres, and retailers in  
the short and medium terms through improved green  
performance (1, 7). Benefits of green supply chain initiatives  
include the ability to cost-effectively plan distribution routes  
with suppliers and customers; maximize capacity and move  
full containers; consolidate multiple customer orders and  
eliminate expedited and extra shipping costs for on-time  
delivery while honouring customer delivery dates (3, 6).  
professional activity of gathering and meeting a group of  
people for the purpose of celebration, education, marketing,  
and reunion, and is responsible for conducting research,  
designing activities, planning and coordinating and monitoring  
to realize the presence activities.  
Judging from the types of events held, Event Organizer can  
be categorized into (Wikipedia, Indonesia, 2018):  
One Stop Service Agency: Even a large organizer  
capable of organizing various types of events up to an  
international scale.  
MICE: Short for Meeting, Incentive, Convention,  
Exhibition). Even Organizer which specializes in organizing  
events in the form of meetings.  
Brand Activation; is an Even Organizer that specifically  
helps its clients to promote in order to increase sales, increase  
brand recognition among consumers, by interacting directly  
with their target market.  
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Music and Entertainment: Even Organizer which  
specializes in entertainment, especially music.  
Wedding Organizer: Even Organizer that specializes in  
helping clients hold weddings.  
Birthday Organizer: Even Organizer which is an expert  
at making birthday parties including for children.  
Personal Organizer: Special Organizer that moves to  
hold private parties, especially for the rich.  
Indonesian Event Organizer Community, a media  
atmosphere of the performance atmosphere that will be held to  
influence the emotions of the audience  
4. When: Relates to the most appropriate time for  
organizing the event and also considers the flexibility or  
leniency associated with time for research and preparation  
5. What: Regarding how to package this event so that it  
is attractive to the target audience, consisting of the name or  
type of program, the content of the program and the elements  
needed (5).  
promotion event for events and various events.  
3 Methodology/Materials  
This study used a descriptive qualitative method approach.  
According to Sugiono in his book, the qualitative research  
method is a research method based on the philosophy of  
positivity, used to examine the conditions of natural objects,  
where researchers are key instruments, sampling of data  
sources conducted by purposive, collection techniques with  
triangulation, data analysis is qualitative, and qualitative  
research results more emphasis on the meaning of the  
generalisation (17). Bogdan and Taylor (in 11) suggest that  
qualitative methodology is a research procedure that produces  
descriptive data in the form of written and oral words of the  
observed persons and behaviours.  
The object of this research is two companies engaged in  
event organizers in Jakarta, namely Alphabet Event Organizer  
and New Diamond Putra. Alphabet Event Organizer is a  
company that has been established since 1996 and is engaged  
in catering and marriage. While New Diamond Putra is a  
company engaged in wedding organizer since 1990.  
Figure 2: Structure event management hierarchy which consists of an  
event coordinator whose task is as the project coordinator of an event.  
An event planner is a person whose profession is the planning of social  
events. Event managers have the duty to monitor and organize an event  
that can have a positive impact on the target audience. Event Planner  
works in order to ease the Event Planner's workload. The duties and  
responsibilities of the Event Planner are mostly dependent on the tasks  
that are delegated by the Event Planner. (https://www.jobhero.com)  
Sources and data collection in this study through  
observation to companies, documentation, and structured  
interviews with key managers in the company. The structured  
interviews in this study were conducted intensively and  
repeatedly and the informants were free to give answers.  
Structured interviews are designed in the same way as  
questionnaires, except that they are not written questions  
submitted but oral questions made by an interviewer who  
records respondents' answers. The sampling technique in this  
study was purposive sampling and snowball sampling.  
Purposive sampling is a technique of determining samples  
with certain considerations. While snowball sampling is a  
sampling technique of data sources that initially have a small  
amount, the length becomes large. This is done because there  
are many small data sources that have not been able to provide  
satisfactory data, then look for other people who can use the  
data source (17).  
Even Organiser Company usually has several parts. These  
parts include marketing, administration, finance and Even  
Organiser technical parts. The marketing department has the  
task of finding clients for its EO companies. Furthermore, the  
administration section has the task of taking care of all the  
administrative systems needed. The finance department is in  
charge of managing finance from the financial side as well as  
the accountant of the Even Organiser Company. Furthermore,  
for the task of the technical part of the Even Organiser is  
organizing the event to be held. The Production Manager is  
responsible and coordinates all technical production activities  
and prepares a technical production plan as thoroughly as  
possible. Element-Element Events are:  
4
Results and Findings  
Based on the research question of this study, "what is the  
impact of the existence of industry 4.0 on the implementation  
of green supply chain management?", The results of the study's  
authors in this study that the existence of Industry 4.0 has a  
very important and strategic role in the company. In the  
digitized era it also encouraged developments in the small and  
medium industrial sectors.  
1. Why: Relates to the objectives to be achieved in this  
event, especially in meeting the needs and desires of the  
audience  
2. Who: Relates to each person who will be involved in  
this activity, also relates to the target, age group, gender,  
education, and lifestyle  
3.  
Where: Regarding the venue for the event that is most  
appropriate for the target audience, this has an influence on the  
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Figure 3: Green Supply Chain Event Management in the Industry 4.0  
These developments are characterised by (i) the use of a  
combination of information technology networks in the  
production process in small and medium industries, between  
suppliers of event organisers supported by indicators such as  
smart operations, smart logistics, smart warehousing, smart  
data and smart decor so that they will produce smart products  
to provide satisfaction to consumers; (ii) increasing the  
effectiveness and competitiveness of post-automation and  
robotisation industries; (iii) increased productivity and product  
quality; and (iv) reducing the risk of workplace accidents and  
waste reduction and contamination with humans.  
From this description, the author produces a green supply  
chain event management in the industry 4.0 framework shown  
in figure 3. The basis of the green supply chain is the  
integration of environmental management and supply chain  
management to control damaging impacts on the environment  
in the product life cycle through information sharing and  
integrated cooperation. In green supply chain 4.0, one of the  
things that must be explored is the orientation on customer  
satisfaction and needs.  
expand the benefits of internet connectivity that is connected  
continuously. Basically, IoT refers to objects that can be  
uniquely identified as virtual representations in an Internet-  
based structure. In warehouse operations, IoT can assist in the  
management of occupational health and safety aspects, such as  
sensors installed in Material Handling Equipment (MHE) that  
can be connected to a device that will provide information if  
MHE travels at a speed beyond the boundary and or crashes  
into something. complete with location information, hours and  
drivers. In the aspect of inventory accuracy, IoT can help  
calculations with a high degree of accuracy also not involving  
a lot of human power. As with the use of sensors contained in  
each racking that can provide information on the number of  
products contained in the racking in real-time (15).  
4.2 Smart Supplier/Vendor  
The Supply Chain Management Strategy is the main  
backbone and plays a very important role in the operation of  
event management. The coverage of smart vendors/suppliers  
plays an important role in determining product quality, costs,  
product development, and access to finance for companies.  
Quality of products and services, as a determinant of customer  
satisfaction, one of which depends on the quality of selected  
suppliers. Quality supplies certainly make it easier for  
companies to produce quality products and services as well so  
that they will have an impact on the company's performance  
management events and on competitors.  
4
.1 Internet of Think and Service (IoT)  
The role of information in the green supply chain is very  
important. Information consists of data and analysis related to  
inventory, transportation, facilities, and customers throughout  
the supply chain. The information provides management with  
the opportunity to make supply chains more responsive and  
efficient. Information is potentially the biggest driver of supply  
chain performance. Components of decisions regarding  
information are (4).  
Currently, in the industrial era 4.0 all companies,  
especially event management, are included in the internet-  
based information technology era. Internet of Things or  
commonly known as abbreviation IoT is a concept that aims to  
4.3 Smart Event Management  
In the event management is also an important thing,  
because good management will be one factor in an event to be  
successful and consumers become satisfied. The important  
role of management in event management is to clarify the role  
of each division, for example, what is the role of the logistics  
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division? What is the role of the operational part? what is the  
role of Big Data division? What is the role of the decor  
division? So it is necessary to have a clear role and focus in  
managing an activity, without any good organization regarding  
tasks between divisions, of course, the functions of each  
division will overlap.  
In every Event Organiser, there must be people who  
understand the organization of events ranging from A to Z.  
Usually, experience and flight hours are high. Skill is already  
qualified and have a sense and feeling sensitive to potential  
problems that usually arise in the world of Event Organiser.  
Anything related to the technical event of his position is held  
by a Production Manager. Stage, Light system, Sound System,  
Front of House, Security, tents, electricity, and others.  
Production Manager has several people who act as his right  
hand. There is a right hand handling the stage, or lighting, or  
sound system, or security/security, or electricity and others.  
Coordinate is the keyword in this division. Positions under  
Production Manager such as; Assistant Production Manager,  
Traffic Management Officer, Administration Officer  
5
Conclusion  
Environmental pollution is a major problem that has the  
potential to cause the extinction of mankind on earth if it is not  
immediately addressed. For this reason, a green supply chain  
framework is needed which is expected to provide ideas or  
ideas for event management companies in making long-term  
decisions so that sustainable corporate goals will be achieved.  
At present, the development of the event management  
industry which tends to increase and the increasing consumer  
awareness of the environment and the issue of an  
environmentally sound industry concept has forced the  
industry to adapt to the green industry concept in every  
business process, which later developed into GSCM.  
The industrial revolution 4.0 took a big leap in the  
industrial sector especially in companies engaged in service  
companies such as event management, where information and  
communication technology was fully utilized. In order to be  
able to compete, companies must be able to adopt this Industry  
4.0 and prepare the right strategies in all departments. The past  
year has shown a gradual transition from the Supply Chain  
Industry to an environment-based green supply chain that is  
controlled by tech-driven. This means that there has been a  
rapid change in technology in the form of the Internet of  
Things (IoT), Artificial Intelligence or Artificial Intelligence  
(
(
Production Finance Officer), Production Finance Officer  
arranging everything related to production finance), Venue  
Coordinator (set everything related to venue / event location),  
Security Coordinator (arranging everything related to event  
security), Stage Coordinator (set everything related to stage),  
Lighting System Coordinator (arrange everything Something  
related to lighting), Vendor Coordinator (arranging everything  
(
AI), Automation, Robots, and Big Data which directly affects  
logistics personnel and operating procedures.  
So the author's analysis of 2 (two) event management  
companies that exist in Jakarta, (New Diamond and Alphabet)  
then with the presence of the industrial revolution 4.0 is very  
helpful in improving the performance of the company. Even  
the rapid advancements in the Industrial Age 4.0 with Big  
Data, Artificial Intelligence (AI), and the Internet of Things,  
how to transact will be very fast and efficient in the future  
besides it will provide more capabilities for vendors / suppliers  
to visualise potential problems, find solutions alternatives, and  
understand the impact of company event management  
decisions to improve operational reliability to a new level, so  
that all problems will be avoided early.  
related to vendors  
/ suppliers etc.), General Support  
Coordinator (regulates all the general things related to  
production). (Sutawidjaya, Conference on Interdisciplinary  
Business and Economics Research, Osaka, Japan, 2017)  
4.4 Delivery  
Delivery stage, the stage where the company is ready to  
launch products to consumers. The processes involved include  
handling orders from customers, choosing a shipping service  
company, handling warehousing of finished products and  
sending bills to customers.  
At this stage of Event Organizer, activities must prioritize  
quality and not profit. The consumer has proven the quality of  
the work of the Event Organization, then on another occasion,  
the Event Organizer will also be used again. In addition, other  
parties will have the ability to become a new client.  
Acknowledgements  
The author expresses many thanks to the management of  
the New Diamond, Jakarta event organizer and the event  
organizer Alphabet Management in Jakarta, which has helped  
many writers in providing the data needed in writing this  
article.  
(
Sutawidjaya, Conference on Interdisciplinary Business and  
Economics Research, 2017).  
4
.5 Smart Consumer  
The industrial era 4.0 made changes to consumer  
References  
1
.
Ahi P, Searcy C. A comparative literature analysis of definitions  
for green and sustainable supply chain management. Journal of  
cleaner production. 2013 Aug 1;52:329-41.  
behaviour from before the digital age.  
This group in choosing products always pay attention to  
the values given by a product. Consumers in this group pay  
attention to the benefits obtained when compared to the prices  
or costs incurred. Smart Consumers need commitment in smart  
products that are produced by event organizer companies,  
smart consumers need more clear or accurate information so  
that consumers can track information on the existence of goods  
and the range of services provided by event organizer  
companies.  
2
.
Achmad H Sutawidjaya. Conference on Interdisciplinary  
Business and Economics Research, Osaka, Japan. 2017.  
3. Akhavan P, Elahi B, Jafari M. A new integrated knowledge model  
in supplier selection: The case of an Asian automotive supply  
chain. Education, Business and Society: Contemporary Middle  
Eastern Issues. 2014 Oct 28;7(4):333-68.  
4
.
Chopra S, Meindl P. Supply Chain Management: Strategy,  
Planning, and Operation. Second Edition, Person and Prentice  
Hall, New Jersey. 2004.  
5
.
Chusnu Syarifa Diah Kusuma. Event Management Module,  
Universitas Negeri, Jogjakarta. 2016.  
2
12  
Journal of Environmental Treatment Techniques  
2020, Volume 8, Issue 1, Pages: 207-213  
6
7
.
.
Elahi B, Etaati L, Seyed-Hosseini SM. An integrated modeling for  
supplier selection and optimal lot sizing: a case study of four-  
echelon supply chain. InFirst International Technology  
Management Conference 2011 Jun 27 (pp. 877-884). IEEE.  
Elahi B, Franchetti M. Optimization modelling for green supply  
chain planning. InProceedings of the 106th Air and Waste  
Management Association (AWMA) annual conference 2013 (Vol.  
7
8).  
8
9
.
.
Goldbatt Joe. Special Event - Third Edition.New York: John  
Wiley and Sons. 2002.  
Hervani AA, Helms MM, Sarkis J. Performance measurement for  
green supply chain management. Benchmarking: An international  
journal. 2005 Aug 1;12(4):330-53.  
1
1
1
1
0. Machado C, Davim JP. Green and lean management. Springer.  
017.  
1. Moleong, Lexy J. Qualitative Research Methodology: Bandung:  
Rosdakarya. 2007.  
2. Moleong, Lexy J. Qualitative Research Methodology. Bandung:  
Teenager Rosdakarya. 1994.  
3. Kleindorfer PR, Singhal K, Van Wassenhove LN. Sustainable  
operations management. Production and operations management.  
2
2
005 Dec;14(4):482-92.  
1
4. serambinews.com, Opportunities, and Challenges of the Age of  
the Industrial Revolution 4.0.  
1
1
5. Puput Suwastika MM. PPM Manajemen. 2018.  
6. Sung TK. Industry 4.0: a Korea perspective. Technological  
forecasting and social change. 2018 Jul 1;132:40-5.  
1
7. Sugiyono, S. Research Method Quantitative and Qualitative  
R&D, Alfabeta, Bandung. 2010.  
2
13