Regional transportation development for development at fertilizer plants in North Sumatra (case study)

. Supply chain activity has an opportunity for the occurrence of risk. Therefore, risk management is needed in the handling of risk with the aim to minimize the risk level and impact of those risks. PT. XYZ of PT Pupuk Indonesia (Persero) engaged in the fertilizer industry. The main product produced is urea fertilizer. In the production process, the factory is supported by adequate production facilities and international standard technology. Currently, PT XYZ does not yet have risk management which explicitly discusses the proposed risk management along with the handling strategies required by the company. By looking at the current condition of the company, in order to achieve the goals to be achieved the company needs a good supply chain planning such as by identifying the risks that exist in the supply chain and preventive measures. Performed risk analysis and evaluation of potential supply chain companies using HOR (House Of Risk) tools. After the research there were 42 risk events and 42 risk agents. With the 80/20 pareto approach, 9 risk agents are planned for mitigation action. There are 11 recommended risk mitigation actions recommended to the company in the hope of addressing the risk of urea fertilizer supply chain.


Introduction
A supply chain can be defined as a network which consist of several companies (including suppliers, manufacturers, distributors and retailers) who cooperate and both directly or indirectly engaged in achieveing customer's demands. Supply chain activity has an opportunity for the occurrence of risk. Therefore, risk management is needed in the handling of risk in the aim to minimize the level of risk and risks' impact [1].
PT XYZ is a subsidiary company of PT Pupuk Indonesia (Persero) engaged in the fertilizer industry. The main product is urea fertilizer. In the production process, the factory is supported by adequate production facilities and international standard technology. Vendors are an important part of supply chain management in PT XYZ because all production materials, both auxiliary materials for production, chemical additives to production machines' spare parts are supplied by selected vendors after a tender / auction. Initial observations showed that there was a delay in the delivery of helping chemicals from 2 days to 106 days. Another problem found in the company is the failure of the bidding process, so that the bidding done repeatedly and resulted the length of the PR process time until the issue of PO and the document confirmation of the specification of the working unit is not available [2][3].
Currently, PT XYZ still does not have any risk management that explicitly discusses the proposed risk management along with the handling strategies required by the company. By looking at the company's condition today, in order to achieve the goals, the company needs a good supply chain planning such as by identifying the risks that exist in the supply chain and preventive measures. Therefore, this research identifies potential risk events occurring in a supply chain, what factors cause the risk to occurs, the relationship between these factors and risks, and how the handling strategy can be used in PT XYZ to handle the risks that usually occur in the supply chain.
In this research will be analyzed and evaluated the risk that potentially appears on the company's supply chain using the HOR (House Of Risk) tools developed by Pujawan and Geraldin. The concept of HOR is similar to the House of Quality (HOQ) concept derived from the Quality Function Deployment (QFD) method. According to Geraldin [4], the HOQ concept will help to design strategies, to identify risks and prioritize risk events that must be addressed first and design a mitigation strategy to reduce or eliminate identified risk agents.
This research is needed for local development. This is necessary for the development of the North Sumatra region, where transportation problems are very influential on product delivery. The company is currently experiencing supply chain problems that affect the timeliness of product acceptance to consumers.
Research on risk mitigation applying the House of Risk (HOR) approach has been conducted and published in a journal entitled "Analysis and Improvement of Risk Management Supply Chain of Rafting Sugar Supply With House Of Risk Approach" and Managing Quality Risk in A Frozen Shrimp Supply Chain: A Case Study [1,9].

Research method
The research begins with the review and data collection at PT. XYZ. Data obtained through interviews are mapping of company activity based on SCOR model, assessment of severity on risk event, assessment of occurence on risk agent, relationship assessment at risk event with risk agent, mitigation action, assessment of difficulty level on mitigation action and correlation relationship between risk agent with mitigation action [5].
The method used in this study is the approach of House of Risk (HOR) which consists of 2 phases. House of Risk Phase I has the following stages: 1. Identify the risk events that can occur in every business process. Performed through supply chain mapping (plan, source, make, deliver and return). 2. Estimate the impact of some risk events (if they occur) ie Severity (Si). 3. Identify the source of risk and assess the probability of occurrence of each risk source ie Occurence -Oj-. 4. Calculate the relationship of each risk source and each risk event. 5. Calculate the potential aggregate risk group (ARPj) with the formula ARP j = Oj Σ Si Rij. 6. Rank risk sources based on a collection of potential risks. While House of Risk Phase II has the following stages: 1. Select multiple risk sources with a high priority ranking that may use pareto analysis from ARPj. 2. Identify consideration of relevant actions for the prevention of sources of risk. 3. Determine the relationship between each preventive action and each source of risk-Ejk-. 4. Calculate the total effectiveness of each action as follows TEk = ΣARPjEjk. 5. Estimate the degree of difficulty in performing each action. 6. The priority ranking of each action (Rk) in which rank 1 gives the highest meaning of action with ETDk.

Identification of risk event and risk agent
Risk identification is a stage to know the risk event that interfere with supply chain activity at company and to know risk agent that cause risk event identification is done through interview at PT. Fertilizer Iskandar Muda. Risk event obtained by mapping of supply chain activity based on SCOR model, then Severity rating for every risk event. The result of risk event identification and assessment can be seen in Table 1.
The scale used in the severity scores is a scale of 1-10 with the meaning of value 1 (no disturbance effect) and value 10 (risk of causing harmful interference) [6]. conducted at the time of interview with the PT. XYZ by giving the value of occurence on the assessment form. The result of risk agent identification and assessment can be seen in Table 2. The scale used in the value of occurence is the scale of 1-10 with the meaning of value 1 (The occurrence of the cause of risk is almost not happening) and the value of 10 (The occurrence of the cause of risk almost always occurs) [6].
Assessment level of risk event relationship with risk agent conducted during interview with PT. XYZ by way of giving relatonship value on the form. The scale used in the relationship value is 0, 1, 3 or 9 where 0 indicates no relationship, 1 low (low), 3 moderate, and 9 indicates high ties [6].

Calculation of Aggregate Risk Potential (ARP)
ARP calculations are obtained based on the formula:

1 st Phase house of risk
House of Risk Phase I is used to determine which risk agents are prioritized for mitigation action. With the 80% -20% pareto approach, 20% of the risk causes will impact 80% of potential risk, from Figure 1. above can be seen 9 risk agent of 21% which gives an impact of 80.58% against the potential risk, 9 such risk agents: 1. Shut down production (A27). 2. Sudden material demand (A28).

2 nd Phase house of risk
Upon the completion of the HOR of Phase, the second Phase is conducted to produce risk mitigation actions to handle priority risk agents in Phase IHOR. [8][9] Based on the results of the 9 priority risk agents that will be addressed, 11 risk mitigation actions are made: 1. Provision of adequate spare parts (PA1). 2. Coordination and confirmation of specification of goods / spare parts with the user (PA2). 3. Agreement with PT. Perta Arun Gas on the provision of emergency gas derived from regasifikasi (PA3). 4. Improved coordination between parts (PA4). 5. Schedule and perform preventive maintenance and predictive maintenance (PA5). 6. Turning the Around Factory (per ± 18 months) (PA6). 7. Substitute equipment / spare parts of factories that have been obsolete (PA7). 8. Improve the performance of production planning and inventory control (PA8). 9. Tighten cooperation, collaboration and information (PA9). 10. Provide power generator / generator set for production purposes (PA10). 11. Coordination with utility unit of power plant (PA11). In HOR Phase II, Total Effectiveness is calculated. Total effectiveness can be calculated based on the formula: TE k = ΣARP j E jk TE 1 = [(1813·3)+(1044·3)+(1044·3)] = 11703 Furthermore, TEk calculation is entered into House of Risk Phase II. The value of Effectiveness (level of relationship between mitigation and risk agent) is 0, 1, 3 or 9 where 0 indicates the absence of linkage, 1 low (low), 3 moderate, and 9 indicates high ties [4].
After the calculation of TEk then calculate the Effectiveness to Difficulty Ratio which can be calculated by using the formula: The scale used in the Difficulty score is a value of 3, 4, 5 with the meaning of value 3 indicating low difficulty, moderate 4 and 5 showing high difficulty [4]. Assessments and calculations on risk mitigation actions are incorporated into Phase II HOR as in Table 3.