Mitigation of gayo arabica coffee supply chain risk using the house of risk method in Aceh Tengah

Aceh Tengah District is the largest Gayo Arabica Coffee production area in Aceh Province. Therefore, coffee has an important role in the economy of the people of Aceh Tengah, both as a source of income for coffee farmers, a source of foreign exchange and as a provider of employment through processing, marketing and trading activities. However, Gayo Arabica Coffee farmers are often faced with many obstacles and risks in run their business. The aim of this research is to analyze the risks with the highest impact on the Gayo Arabica Coffee supply chain and formulate mitigation to reduce the risk impact on it by using the House of Risk (HOR) method. Based on the research results, 42 risk events and 37 risk agents were obtained and 7 dominant risk agents were obtained which could be prevented with 9 mitigation strategies. The risk with the highest impact on the Gayo Arabica Coffee supply chain in Aceh Tengah District is assessed based on the highest to lowest Aggregate Risk Potential (ARP) value using the 67:20 Pareto Diagram. Mitigation strategies for Gayo Arabica Coffee supply chain risks in Aceh Tengah District are assessed based on the Effectiveness to Difficulty (ETD) value from highest to lowest.


Introduction
In 2023, Aceh Tengah District will have the largest Arabica coffee plantations in Aceh Province with a land area of 49,835 ha and production of 35,255 tonnes with an average production of 813kg/ha [1].The extensive coffee plantation land makes Aceh Tengah District the largest Gayo Arabica Coffee production center in Aceh Province and makes the people depend for their livelihood on the agricultural sector, especially the coffee commodity plantation subsector [2].Therefore, coffee has an important role in the economy of the people of Aceh Tengah, both as a source of income for coffee farmers, a source of foreign exchange and as a provider of employment through processing, marketing and trade (export and import) activities [3].
However, Gayo Arabica Coffee farmers are often faced with many obstacles and risks in running their business [4].The aim of this research is to analyze the risks with the highest impact on the Gayo Arabica Coffee supply chain and formulate mitigation to reduce the risk impact on the Gayo Arabica Coffee supply chain using the House of Risk (HOR) [5].1297 (2024) 012064 IOP Publishing doi:10.1088/1755-1315/1297/1/012064 2 A supply chain is a network of companies that work together to produce and deliver products to end users.Risk is a danger, result or consequence that can occur as a result of a process that is ongoing or will be ongoing or in the future; the possibility of loss or being in a dangerous condition.Risk mitigation is a systematic methodology used by management to reduce risk [6].

Research methods
This research will be carried out in Pegasing, Bebesen and Bintang subdistricts, Aceh Tengah District in March 2023.The research location was chosen purposively with the consideration that Aceh Tengah District is the largest Gayo Arabica Coffee producing area in Aceh Province.
The object of this research is the actors in the Gayo Arabica Coffee supply chain consisting of farmers, collectors and export companies in Pegasing, Bebesen and Bintang Districts, Aceh Tengah District.The scope of this research focuses on risks and the high and low levels of risk faced by actors in the supply chain as well as mitigation in overcoming the risks posed in the Gayo Arabica Coffee supply chain in Aceh Tengah District.
The sampling technique for farmers, collectors and exporting companies was carried out using purposive sampling.Purposive sampling is a sample determination technique based on the researcher's consideration of which sample is the most useful and representative using certain criteria.The criteria that must be met are as follows [7]: a.All supply chain actors are in one supply chain network b.The products produced are actively exported Based on the criteria that must be met in sampling, the number of samples obtained was 99 farmers, 7 collectors and 2 exporting companies which are CV.Oro Kopi Gayo and CV.Asa Coffee Gayo.
The types of data used in this research are primary and secondary data.The data collection method used in this research was using direct interviews with the samples in this research.The analytical methods used in this research were: 1. To Analyze the risks that have the greatest impact on the Gayo Arabica Coffee supply chain in Aceh Tengah District using the House of Risk (HOR) phase 1 method.
2. Formulating risk mitigation in Gayo Arabica coffee supply chain in Aceh Tengah District House of Risk (HOR) phase 2 method [5].
The following are the steps in analyzing the first objective: a. Identify business processes and risk events.Identification of risk events is carried out by mapping business processes with the SCOR (Supply Chain Operations Reference) [8] .

b. Identify risk agents
Risk agents are things that can cause previously identified risk events to occur.c.Identify the impacts that will be caused Once the risk agent is known, proceed to identify the impact that will result from the risk that occurs.Next, provide a value for the severity of the risk that occurs using severity (S) on a scale of 1-10 as in Table 1.e. Provide an assessment of the correlation between each risk event and each identified risk with the risk agent (Rij) on a scale (0,1,3,9) as in Table 3. = severity value / level of impact of the risk event Rij = correlation between risk i and risk agent j g.Sequencing Risk Agents Sort agents or risk causes based on highest to lowest ARP value.The second problem is formulating risk mitigation in Gayo Arabica coffee supply chain in Central Aceh District House of Risk (HOR) phase 2 method.The following are the steps in analyzing it: a. Choosing a Risk Agent The selection of several risk agents is based on the Pareto diagram, which contributes approximately 67% of the ARP value.

b. Identify Mitigation Strategies
Identify appropriate mitigation strategies for each previously selected risk agent by conducting interviews with respondents.

c. Mitigation Strategy Assessment
Determining the magnitude of the correlation between risk agents and risk mitigation strategies using the scale (0,1,3,9) in Table 5 correlation scale and determining the level of difficulty of the mitigation strategy (Dk) using the scale (3,4,5) as in After obtaining the mitigation design, weighting the value of the correlation between the mitigation strategy and the dominant risk agent as well as the degree of difficulty obtained from the interview is continued by calculating the effectiveness value (TE K / Total Effectiveness ) of the mitigation strategy.The TE K value is obtained from the multiplication of the ARP value and the correlation value between the risk agent and the mitigation strategy as in equation (2).
Where: TE K = Total effectiveness of each action ARP j = Aggregate Risk Potential E jk = Correlation value of the strategy with the risk agent The next step is to determine the ratio value (ETD K / Effectiveness of Difficulty) to determine the effectiveness and difficulty ratio in implementing each mitigation action.The ETD value is obtained through the ratio TE K and the level of difficulty (D K ) as in equation (3).
Where: ETD K = Total effectiveness degree of difficulty TE K = Total effectiveness of each action D K = Degree of difficulty e. Determining Mitigation Strategy Priorities Mitigation strategy priorities are arranged based on the largest to smallest ETDK values .

Results and discussion
This research was conducted in one of the best coffee producing areas in Aceh Province; Aceh Tengah District.Aceh Tengah District consists of 14 districts, 20 sub-districts and 295 villages.Administratively, the area is 444,404.13ha, geographically located at 040 10' 33'' -050 57' 50'' N latitude and 950 15' 40'' -970 20' 25'' E longitude with altitudes ranging from 100 m to with 2000 masl.Aceh Tengah District is an area with a tropical climate, cool climate with temperatures ranging from 20.10 0 C [9].
Arabica coffee has become one of farmers' mainstay commodities, this is because the geographical location of Aceh Tengah District is very suitable for growing conditions for Arabica coffee plants.The research area consists of 3 districts out of 14 sub-districts in Aceh Tengah District.The area study were Pegasing, Bebesen and Bintang district which are Arabica coffee producing areas in Aceh Tengah District with the highest production and productivity.
The main actors in the Gayo Arabica Coffee supply chain in Aceh Tengah District consist of farmers, collectors and Arabica coffee exporting companies.The following is the supply chain network structure for Gayo Arabica Coffee in Aceh Tengah District [10]: Where : = Flow of Goods/Products/Activities = Financial/Financial Flow = Information Flow Based on the picture above, it can be seen the relationship of each supply chain actor with the flow of goods, financial flow and information flow.The flow of goods in the Gayo Arabica Coffee supply chain occurs from upstream to downstream.Financial flows occur from downstream to upstream, namely from final consumers to farmers.The flow of information moves from upstream to downstream and from downstream to upstream [11].House of Risk Phase 1  After mapping the supply chain activities, it was continued by identifying risk events and assessing the level of impact of risk events (severity) that occurred in supply chain activities.It can be seen that the highest severity score with a value of 9.Meanwhile, the risk event that has the lowest severity value with a value of 2. The number of requests has fallen 8 A37 Low quality coffee beans 6 After identifying risk events, continue to identify risk agents or causes of risk events and assess the level of possibility of risk agents occurring in supply chain activities.
Based on the table above, it can be seen that being exposed to rainwater and decreasing demand becomes the risk agent that has the highest occurrence value with a value of 8.Meanwhile, nature, accidents and cargo ships not being available become the risk agent that has the lowest occurrence value with a value of 1. Then the value is calculated Aggregate Risk Potential (ARP).ARP is used as consideration to determine risk agents that need to be treated, provided with prevention or provided with mitigation strategies for risk agents.The higher the ARP value, the greater the risk that needs to be handled.Determining priority categories is carried out using a Pareto diagram known as the 80:20 law, namely 80% of company losses are caused by 20% of crucial risks.The use of the percentage 80:20 is not absolute [12].The use of the figure 80:20 is not absolute depending on the company's conditions.In this study, using a percentage of 20% from 37 risk agents, 7 priority risk agents were obtained with the highest ARP value in the percentage range of 18.9% rounded up to 20% or 67:20.This means that 67% of losses are caused by 20% of crucial The consideration of using 20% is because the results of the ARP assessment fall into the priority category where the effective peak difference between the risk agent and the risk posed is 67%.This 20% percentage is a crucial risk in the Gayo Arabica Coffee supply chain in Aceh Tengah District.

House of Risk Phase 2
Those included in the ARP value calculation for the 20% category of the Pareto diagram are low quality (A37) with a value of 2772, climate and weather changes (A1) with a value of 1981, exposure to rainwater (A16) with a value of 856, not paying attention to the level of fruit maturity (A12 ) with a value of 819, simultaneous harvest (A6) with a value of 540, low maintenance of coffee plants (A3) with a value of 504 and non-uniform varieties (A22) with a value of 420.
After obtaining priority risk agents that must be mitigated, proceed with designing a mitigation strategy.The Total Effectiveness (TeK) calculation is carried out.The total effectiveness (TeK) calculation is obtained from the results of the correlation assessment between the risk agent and the mitigation strategy implemented.The TeK calculation shows the level of effectiveness in the process of implementing the mitigation strategy carried out.Then an assessment of the degree of difficulty (Dk) is carried out.The degree of difficulty (Dk) assessment is a measurement of the level of difficulty of the mitigation strategy that will be implemented.Then the effectiveness to difficulty (ETD) ratio is calculated .Effectiveness of Difficulty (ETD) calculations are used to help determine strategic priority ranking of predetermined mitigation strategies.Based on the table above, it can be seen that the sequence of mitigation strategies in the Gayo Arabica Coffee supply chain in Aceh Tengah District based on the Effectiveness to Difficulty (ETD) value from highest to lowest is harvesting coffee according to the harvest cycle, harvesting only ripe fruit ( P6) with a score of 10773, implementing Good Agricultural Practice in coffee cultivation (P8) with a score of 8857, cultivating coffee plants with uniform varieties with regional division (P9) with a score of 6741, socializing natural disaster mitigation (P3) with a score of 4753, providing counseling and SOP training (production, storage, drying, packing and shipping) (P1) with a score of 4494, applying coffee cultivation techniques that are adaptive to climate change (P4) with a score of 4457, building good

Figure 1 .
Figure 1.Supply chain network structure for gayo arabica coffee in Aceh Tengah District.

Figure 2 .
Figure 2. Pareto arp diagram of gayo arabica coffee supply chain risk in pegasing, bebesen and bintang districts, Aceh Tengah District.

Table 1 .
Risk assessment using severity levels.

Table 2 .
Assessment criteria occurrence rate.
f. Calculating the ARP (Aggregate Risk Potential) value ARP calculated by using severity, occurrence, and correlation value which determined previously.ARP is used to prioritize handling agents or causes of risk.Equation (1) is the formula for calculating the ARP: =    (1)Where: ARPj = Aggregate Risk Potential Oj = Occurrence value / probability value of the risk agent occurring Si

Table 4 .
Mitigation strategy assessment criteria.

Table 5 .
Mapping supply chain activities using the scor model.
Mapping Gayo Arabica Coffee supply chain activities using the Supply Chain Operations Reference (SCOR Model); supply chain activity mapping is divided into Plan, Source, Make, Deliver and Return.

Table 6 .
Identification of risk events.

Table 7 .
Identification of risk agents.

Table 9 .
Calculation of the effectiveness to difficulty (etd) ratio.