Risk Mitigation on Infrastructure Port Project Construction (Case Study: Sanur Port Project, Bali, Indonesia)

. Port construction projects have complex work stages and high dependence on internal and external conditions so that the emergence of risks that can cause project delays is elevated. Therefore, it is necessary to apply risk management to identify and overcome the risks that will come. This research uses the Analytic Hierarchy Process (AHP) method to rank risks and determine the most dominant risk parameters for risk analysis. This study shows there are 4 dominant delay risks parameter on the Sanur Port project, with the most dominant risk parameter is the high wave parameter. The effect of high wave risk on the Sanur Port construction project is the delay in project work for 98 days. To reduce the impact of risks that may occur, risk mitigation is carried out on aspects of workers, tools, and methods of implementation.


Introduction
Port development projects have complex work stages and high dependence on internal and external project conditions, causing the potential for delays to occur in project implementation to be higher [1]. One of the causes of delays in a construction project is the emergence of unexpected risks in one or several stages of construction [2]. The risks contained in the project cannot be eliminated but can be reduced by systematic risk analysis, namely by identifying, analyzing, and responding to project risks [3].
In the risk identification process using a method known as the Lookup Method, this method is in the form of making a risk checklist based on risk data identified on projects that have been done previously. This method is straightforward to apply and can help identify risks in detail [4]. Meanwhile, in the risk ranking analysis based on the impact assessment and risk frequency using the AHP (Analytic Hierarchy Process) method. Analytic Hierarchy Process (AHP) is a structured technique that aims to organize and analyze complex decisions, this method is an accurate approach in measuring the weight of decision criteria [5].
In the Sanur Port construction project, there has been a delay due to being late in dealing with the tidal wave problem at the time of carrying out the survey work. Geographically, the Port of Sanur is in the southern waters of Indonesia and is part of the Indian Ocean with the characteristics of the farthest sea waves [6]. Therefore, it is necessary to do risk analysis in the Sanur Port construction project. The aim is to identify dominant risk parameters, dominant risk impacts and determine risk mitigation methods that may cause delays in the Sanur Port project.

Methods
At this stage, the risks that can cause delays in the Sanur Port construction project are carried out. The identified risks are the risks involved in the work on the critical path analysis. This identification is carried out based on a literature study of several journals that discuss the risks in port construction projects using the Lookup method. Critical path analysis using the Critical Path Method (CPM) with the analysis stages include activity grouping based on WBS and assigning a code or numbering to each job to facilitate the preparation of Network diagrams; Network Diagram based on the relationship and duration of each work by the project implementation logic framework; The critical path of the project can be determined based on the total float value of each activity (total float = 0).
In the risk identification process using a method known as the Lookup Method, this method is in the form of making a risk checklist based on risk data identified on projects that have been done previously. This method is straightforward to apply and can help identify risks in detail. Meanwhile, in the risk ranking analysis based on the impact assessment and risk frequency using the AHP (Analytic Hierarchy Process) method. Analytic Hierarchy Process (AHP) is a structured technique that aims to organize and analyze complex decisions, this method is an accurate approach in measuring the weight of decision criteria.
Risk assessment is carried out on the frequency and impact of risk using the likelihood scale according to Table 1 and Table 2. Risk assessment is carried out by distributing questionnaires to service providers and supervisory consultants with a target of 10 respondents with the following criteria: a. Have 3 years of working experience in the same position. b. Have work experience in port construction projects.

Data collection
The data collected in this study consisted of several types of data, such as primary data as the S curve of the Sanur Port project obtained from competition documents; secondary data as research variables; and qualitative data as statements or values obtained from the results of distributing questionnaires and are subjective. Secondary data are sourced from documents on procurement of construction work, design, and construction of the port facilities in Sanur, Denpasar, Bali Province that have been signed by the Directorate General of Sea Transportation. Primary data in this study were obtained from a questionnaire of expert who were involved in the Sanur Port Project in Denpasar, Bali.
The location study is in Sanur Port, Bali Province, Indonesia. The location of the port is at 08°04'40'' South Latitude to 08°50'48'' South Latitude and 114°25'53'' East Longitude to 115°42'20'' East longitude. The port will be developed into tourism port that connects Bali to Nusa Penida Island (Fig. 1). The data collected in this study consisted of several types of data, such as primary data as the S curve of the Sanur Port project obtained from competition documents; secondary data as research variables; and qualitative data as statements or values obtained from the results of distributing questionnaires and are subjective. Secondary data are sourced from documents on procurement of construction work, design, and construction of the port facilities in Sanur, Denpasar, Bali Province that have been signed by the Directorate General of Sea Transportation. Primary data in this study were obtained from a questionnaire of expert who were involved in the Sanur Port Project in Denpasar, Bali.

Risk assessment
The high category risks resulting from the risk rating are grouped according to the risk type parameters listed in Table 4. Thus, the most dominant risk parameters can be determined (Table 4). Based on the most dominant risk parameters obtained from the results of the risk rating analysis, then an analysis of the impact of the most dominant risk parameters on the project duration is carried out [7]. This analysis is carried out to analyze how much additional duration can be caused by the most dominant risk parameter on the project duration. After obtaining the most dominant risk causing delays in project implementation, it can be continued by determining the risk mitigation efforts. The determination of this mitigation method is based on a literature study related to these risk variables. The results based on literature studies -journals with similar topics show that there are 50 risks on the critical path that can cause delays in the Sanur Port development project.
Preparation of project scheduling using the Critical Path Method (CPM) with Network Diagram type Activity on Arrow (AOA) based on the S curve data of the Sanur Port project. The critical path in the Sanur Port Project consists of 14 work items which are a series of work on the southern breakwater with a total duration of 819 days (Fig.2).
Respondents for this risk assessment consist of service providers and consultants who oversee the Sanur Port project, with a target number of 12 respondents (Fig.3). Based on the respondent's profile in Figure 3, a work experience dependence test on the respondents' answers using the Kruskal-Wallis method. The results of the Kruskal-Wallis test show the probability value of all variables > 0.05. So, it can be concluded that there is no difference in the perception of respondents' answers based on work experience background. Based on the respondent's profile in Figure 3, an education dependency test was conducted on the respondent's answers using the Mann-Whitney method (Fig.4). The Mann-Whitney test results show the probability value of all variables > 0.05. So, it can be concluded that there is no difference in the perception of respondents' answers based on educational background.
Next, the validity test was carried out using the Moment Pearson Correlation method and the reliability test using the Cronbach-Alpha method using the SPSS version 25 program. Based on the test results, the results are presented in Table 5 for the validity test and Table 6 for the reliability test.

Risk rating analysis using AHP method
The first stage in ranking analysis using the AHP method is to create a hierarchical structure. The hierarchical structure in this study is shown in Figure 5.

Risk Frequency
Risk Impact Very High High Medium Low Very Low The next step is to consider the elements of frequency and impact according to Tables 7 and 8. The weighting of elements for each alternative in the risk frequency and risk impact matrix can be seen in Table 9 and Table 10. Table 9. Element weight for risk frequency. The value of the weight matrix can be said to be approach the value of the number of elements (n) and the remaining eigenvalues are close to zero. Calculate the maximum eigenvalue by dividing the total value of the previous vector by the number of values (n). n = 5 = 5,24 From the calculation of the maximum eigenvalue above, the value is close to the value of n with the remaining 0.24, which is close to zero. Thus, it can be concluded that this matrix has been consistent. The next step is to calculate the CRH value to determine the level of accuracy. Based on the results of the calculation of CRH, which is less than 10%, the hierarchy is consistent and has a high level of accuracy. The following are the results of risk ranking based on the final value according to the risk level category in table 3, which are presented in Table 11 below. Risks with a high category from the previous ranking results are then grouped based on the risk parameters in Table 4. The results of the analysis of the dominant risk parameters in Table 12 show four dominant risk parameters: tidal waves, force majeure, weather, and design, with tidal waves being the most important risk parameter. Dominant in the implementation of the Sanur Port project.

Risk impact analysis
Analysis of the impact of tidal wave risk on project duration is carried out by plotting the time of the Based on shipping safety, everything published by Meteorology, Climatology and Geophysical Agency that barges or pontoons can sail safely at a wave height of less than or equal to 1.5 meters, so sea work is carried out during high tide weeks (> 2.5 m occurs) cannot be implemented based on these safety factors. Based on the bar chart with the time of occurrence of waves, there has been an increase in the duration of some work and causing an increase in the duration of the project. The following is an additional duration that occurs in the work of marine facilities at the Sanur Port project due to the tidal wave risk parameter (Fig. 6).

Risk mitigation
There are several steps to handling the most dominant risk parameters so that project objectives can be achieved, especially the timeliness of project completion in accordance with the plan. The following is the risk mitigation that has been identified in terms of workers, tools, and methods of carrying out a literature study on journals and Construction Safety Plan documents (Table 13). Table 13. Risk mitigation [8,9].

Conclusion
Based on the results of research and discussion, several conclusions can be drawn, such as, There are 50 risks on the critical path that can cause delays in the Sanur Port development project. The most dominant risk parameter is the Tidal Wave. The analysis results of the influence of tidal wave risk parameters on the Sanur Port construction project showed a delay in the project duration of 98 days. And several mitigation steps are needed to minimize the impact of risks on aspects of workers, tools, and methods of implementation such as: a. Workers: must have technical competence in the field of Port Project construction. b. Equipment: Determine the appropriate heavy equipment according to wave conditions, inspect and test the equipment based on Construction Safety Standard. c. Construction method: determine the construction method according to tidal wave conditions, optimizing work when wave conditions are normal or low tide according to wave forecast data obtained from the local Meteorology, Climatology and Geophysical Agency.