ANALYSIS OF TIME AND COST CONTROL OF SEDIMENT TRAP CHECKDAM CONSTRUCTION IN BANDUNG AND SUMEDANG REGENCY

: The main objective of construction management is to manage or regulate the implementation of construction projects, so that results are obtained in accordance with what was planned, both the time of implementation, the cost of implementation and the quality produced. In order to achieve the main objectives of construction management, one of the important factors that must be considered is labor productivity. In a construction project the factors that affect labor productivity include wages, time, equipment, formal education, work experience, location of materials, number of helpers (laden) and so on. Controlling the time and cost of this construction was carried out on the CHECKDAM construction project in the Cikeruh area, Jatinangor sub-district, Sumedang, West Java, Indonesia. Previously, Cikeruh Village was included in the Jatinangor District area, which was originally named the Cikeruh sub-district. However, over time, in 2000, the Cikeruh sub-district officially changed its name to the Jatinangor sub-district, West Java, with the aim of knowing the performance of the project. This control is carried out based on completed projects in terms of time and cost control using the concept of Earned Value Analysis which consists of three indicators, namely BCWS, BCWP, and ACWP. This control is carried out on time deviations (SV), deviations from costs (CV), deviations from the total budget (BV). The analysis was carried out in units of weeks (12 weeks). Based on Earned Value analysis, the deviation from the schedule (SV) in the Check Dam Development in Bandung and Sumedang Regencies is 0


INTRODUCTION
Sediment is the main material forming the morphology (topography and bathymetry) of the coast.Sediment comes from the fragmentation (breaking down) of rock.
The split occurs due to weathering(weathering) which can take place physically, chemically, or biologically.Changes in coastal/estuary morphology occur as a result of the movement of sediments that take place through erosion, transport and deposition mechanisms.The displaced sediment is sediment that lies on the surface of the bottom of the waters (Poerbondone and Djunasjah, 2005).
Sedimentation in the coastal environment originates from the presence of sediments originating from the mainland and is basically the main factor in forming the beach.Sedimentation is closely related to the geomorphic agents working in it.The main geomorphic agents that cause or influence the processes and dynamics of coastal waters are waves, currents and wind.Sediment trap, a sediment catchment pond located at pit to capture and precipitate sediment before it enters the sump so that when it is carried out running pumping, the sediment material to be transported will be slightly reduced.Sediment material that enters together with runoff water is calculated based on rainfall data maximum and minimum in 2018 and 2019.
Stokes' law is used to calculate the depositional velocity at sediment trap1 and sediment trap2 based on the diameter of the Go worth grain size scale.Other factors that are calculated are settling time, flow velocity, residence time and percentage of deposition for 4 sediment classes namely gravel, sand, silt and clay.Simple linear regression is used in the deposition time equation with the diameter of the class of sediment particles that enter it sediment trap.Cikeruh River is one of the rivers in Sumedang, West Java.The dynamics of land management in the Cikeruh Watershed (DAS) is a watershed that flows over two regencies, namely Bandung and Sumedang regencies.
Which has very important roles and functions, including supporting economic development and ecological (environmental) functions.The area which is located in the Cikeruh Sub-Watershed consists of settlements, irrigated rice fields, rain-fed rice fields, fields, shrubs, gardens and plantations.However, changes in land use change that occurred in the Cikeruh Watershed from agricultural land to nonagricultural land encouraged the community to pursue their agricultural activities in the upstream area, of course this resulted in a very high level of erosion and sedimentation hazard.
Erosion is any natural release and transfer of rock masses from one place to another by a carrier substance that moves over the earth's surface.While sedimentation is the process of transporting/carrying sediment by a runoff/flow of water that is deposited in a place where the speed of the water slows down or stops, such as in river channels, reservoirs, lakes and areas along the edges of bays/seas (Arsyad, 1989).Erosion can affect land productivity which usually dominates the upstream watershed and can provide impact negative in the downstream watershed (around the river mouth) in the form of sediment products.
Based on the results of research in 2002 by the PPSDAL Research Team at the Unpad Bandung Research Institute, it is known that the calculation of the total erosion hazard using land use or cover maps in the upstream Citarum River Basin is 15,206,301 tons/Ha/year, and one of the Sub Watershed Areas which gave the highest contribution was the Cikeruh Watershed of 2,156,128 tons/ha/year (Mind of the People March 9, 2010).This is due to the use of land that is not in accordance with the potential of the land which does not consider the level of surface erosion, and this is also caused by agricultural activities with very high intensity which are carried out on land with quite steep slopes and conditions without protective vegetation cover against erosion.Erosion is one of the causes of sedimentation, especially in the downstream areas and causes flooding during the rainy season.As for most of the erosion hazard in the study area, in the Cikeruh River Basin, which is as high as 34.66% or an area of 4112.35Ha.
The level of erosion hazard in the study area is very severe with a total area of 5803 Ha or around 48.91%.The potential for sedimentation in the study area, in the Cikeruh Sub-Watershed, which will occur if the total erosion hazard per year is 2,008,571.06tonnes/year is 255,088.53tonnes/yr.As for the thickness of the potential volume sedimentation that is 212657.1m³and the overall thickness potential is 0.936 m/year, where the result is obtained from the potential volume of sedimentation divided by the area that has the potential to be used as a sedimentation area, if the assumption of suspended load thickness is 0.624 m/year and bed load is 0.312 m/year.
Erosion and sedimentation are problems in the sub-water she driver Cikeruh, a very high level of erosion and sedimentation hazard can be controlled or suppressed, one of which is with the participation of the community, for this reason efforts are needed to control it.Efforts to control erosion and sedimentation cannot be carried out alone by the government but need the participation of the community.Does the community participate.
According to Conyers in Supriatna (2000) there are three main reasons why community participation is very important, firstly community participation is a tool to obtain information about the conditions, needs and attitudes of the local community, without the presence of development programs and projects will fail.Second, that public will trust a development program more if they feel involved in its preparation and planning process.Third, it is a democratic thing when the community is involved in every development program.This reason seems clearly implied in the erosion and sedimentation control program, this program is very conducive to the growth of community participation in its implementation.The form of support or community participation in erosion and sedimentation control that is more easily recognized is the form of participation given in the existing implementation.
Therefore it is necessary to conduct research to know for sure.In addition, research can also answer socio-economic conditions, forms of socialization from government and community participation.Then this research will also produce recommendations that can be used as input to related agencies and to the community in the Cikeruh Sub-Watershed.With the condition of the relatively steep Cikeruh river bed, the high flow velocity will be easily eroded, especially at the bottom, the river walls.When the rainy season arrives, the possibility of erosion can be greater.
The dynamics of land management in the watershed system will affect the condition of the river flow, which causes changes in river flow discharge as a watershed output, resulting in changes in environmental quality.The impact that is often seen is land damage due to increased soil erosion and sedimentation.Erosion caused by damage to the vegetation cover causes a hazard for landslides which are a source of sediment deposits if they enter the watercourse.With the river conditions as mentioned above, the Cikeruh River has great potential for flooding, landslides on the river bed and walls, and so on due to the relatively steep slope of the river bed.
With reference to this background, it is necessary to deal with the amount of sediment entering the river.So to control the sediment it is necessary to have land conservation measures.
However, the implementation of this conservation measure has time constraints, where the results are not very significant in the near future.For this reason, it is necessary to construct a Sediment Control Building as a support for safeguarding the Cikeruh Watershed from erosion and sedimentation hazards.The purpose of sediment control for the Cikeruh River is to produce a design for a Sediment Control Building (Check Dam) with the aim of analyzing flood discharge, calculating Check Dam dimensions to reduce sedimentation in the downstream river which causes water to overflow, and determining Check Dam stability.
The construction of the Check Dam on the Cikeruh river is planned to be located at Cikeruh, Jatinangor, Sumedang Regency, West Java 45363.Construction work project sendiment trap Check DAM Sumedang Regency which was carried out by this contractor.The project cost budget is something that causes problems that are often encountered in the implementation of a construction project.Project cost control is important to maintain project performance so that it can be on time, quality and cost.Earned Value Concept is a method for analyzing the project cost performance index to determine the estimated final project budget based on project data in the form of BCWP, BCWS, The relationship between BCWS, BCWP and ACWP can be seen in Figure 1.

Figure 1 Graph of "Earned Value" S Curve Source:
PT. His Excellency the Great Chief

Data Analysis
Analysis of controlling the time and cost of constructing a checkdam settlement trap in Bandung and Sumedang districts uses the Result Value Analysis method based on projects that have been completed for 12 weeks.Value analysis has three basic elements, namely BCWS, BCWP, and ACWP analysis.

Yield Value Analysis a. Deviation Against Time (SV)
To get the SV value for each period, the formula is used:  653,192,002.04(The resulting value of reducing BCWP with BCWS shows a positive value, this can mean that the implementation is faster than the planned schedule).For the calculation of schedule deviations (SV) per week according to point 1, point 2 and point 3, it can be seen in table 3 and the schedule deviation graphs in Figure 1 and Figure 2.  29,424,878.83 8,101,918.69 21,322,960.14 21,726,040.67 3 Week 3 51,997,388.62 99,923,926,200,234.58 4 Week 4 77,794,542.67 187,029,234,435,058.74 5 Week 5 116,288,733.47 320,650,361,796,888.44 6 Week 6 132,815,035.28 97,343,948.47 35,471,325,801.63 7 Week 7 157,604,488.00 309,203,598,924,389.70 8 Week 8 1,031,886,161.81 378,694,159.77 653,192,002.04 197,267,612.34 9 Week 9 496,998,295.90 1,005,968,969,702,175.36 10 Week 10 761,822,205.40 631,909,349.95 129,912,789,319.91 11 Week 11 429,683,847.07 594,946,263,052,338.01 12 Week 12 723,529,554.86 376,477,216.85 347,052,338.010.00 Source: Analysis Results The results of the SV analysis are a representation of the ongoing progress of a project.Basically the SV value represents the actual progress of the work where the value is obtained from the reduction of the actual value (BCWP) with the planning value (BCWS).Implementation is faster than planning if the SV value is positive, if the SV value is negative then implementation can be declared late.

Figure 2 Weekly Analysis Schedule Variance (SV) chart
Source: Results of Analysis Based on Equations.,960,187.66 17,588,968.67 3,371,219.00 3,371,219.00 2 Week 2 29,424,878.83 24,976,335.50 4,448,543.33 7,819,762.33 3 Week 3 51,997,388.62 48,053,062.39 3,944,326.23 11,764,088.55 4 Week 4 77,794,542.67 69,546,782.10 8,247,760.57 20,011,849.12 5 Week 5 116,288,733.47 106,307,726.61 9,981,006.86 29,992,855.98 6 Week 6 132,815,035.28 116,861,107.81 15,953,927.47 45,946,783.45 7 Week 7 157,604,488.00 140,746,927.26 16,857,560.74 62,804,344.19 8 Week 8 1,031,886,161.81 883,740,141.60 148,146,020.21 210,950,364.39 9 Week 9 496,998,295.90 438,141,209.45 58,857,086.46 269,807,450.85 10 Week 10 761,822,205.40 664,546,414.10 97,275,791.30 367,083,242.15 11 Week 11 429,683,847.07 429,944,902.98 366,822,339.17 12 Week 12 723,529,554.86 980,420,891,284.55 109,931,054.61The difference of Rp. 3,371,219.00 in the first week was due to the fact that the money that came out during implementation was lower than the planned weight.This is because the tax expenditure paid at the end of the project affects the deviation in the CV analysis   IDR 20,557,558,968.67 = IDR 2,968,138.46 (This value indicates that the budget issued is smaller than the planned budget).2. For work in the second week BCWS = IDR 8,101,918.69 ACWP = IDR 24,976,335.50 BV = IDR 8,101,976,874,416.81 (This value indicates that the budget issued is greater than the planned budget).For the calculation of schedule deviations (BV) per week, it can be seen in table 5 and the schedule deviation graphs in figures 6 and 7.  8,101,918.69 24,976,874,906,278.35 3 Week 3 99,923,663.87 48,053,062.39 51,870,601.48 37,964,323.13 4 Week 4 187,029,366.83 69,546,782.10 117,482,584.73 155,446,907.86 5 Week 5 320,650,563.17 106,307,726.61 214,342,836.56 369,789,744.42 6 Week 6 97,343,948.47 116,861,517,159.34 350,272,585.08 7 Week 7 309,203,076.06 140,746,927.26 168,456,148.81 518,728,733.88 8 Week 8 378,694,159.77 883,740,045,981.83 13,682,752.05 9 Week 9 1, 005,968,083.61 438,141,209.45 567,826,874.16 581,509,626.21 10 Week 10 631,909,349.95 664,546,637,064.15 548,872,562.06 11 Week 11 594,946,865.17 429,944,750.05 165,002,115.12 713,874,677.18 12 Week 12 376,477,216.85 980,420,943,622.57109,931,054.61To find out the efficiency of the project time, the next calculation is the time performance index or commonly known as (SPI).To display the SPI value for each period, the following formula is used: SPI = BCWP / BCWS ………………………(4.4) With: SPI = Efficient use of resources BCWP = Cost based on completion of work within the time period BCWS = The cost of planning the completion of work in a period of time If the SPI performance index value < 1 means that the time in implementing the project is slower than planned.If the SPI performance index value is > 1, it means that the time for implementation is faster than planned.The greater the difference from number 1, the greater the deviation from planning.The monthly SPI value is obtained as follows: 1) For work in the first week of BCWP = IDR 20,960,187.66 BCWS = IDR 20,557,107.13 SPI = 20.960.187,66/20.557.107,13=1,02 (This value indicates SPI (1.02) > 1, meaning that project implementation is faster than planning) 2) For work in the second week of BCWP = IDR 29,424,878.83 BCWS = IDR 8,101,918.692) For work in the second week BCWP = IDR 29,424,878.83 ACWP = IDR 24,976,335.50 CPI = 29.424.878,83 / 24.976.335,50 = 1.18This value shows CPI > 1, meaning that the expenditure is less than the planned budget 3.
For work in the third week of BCWP = IDR 51,997,388.62 ACWP = IDR 48,053,062.39 CPI = 51.997.388,62 / 48.053.062,39=1,08This value shows CPI > 1, meaning that the expenditure is less than the planned budget.For the calculation of schedule deviations (CPI) per week in the same way as above, it can be seen in table 6, and schedule deviation graphs in figures 7 and 8.

Project Analysis Results
From the project data and the results of the previous analysis, the following data were obtained: Figure 3 Graph Analysis Schedule Variance (SV) Cumulative' Deviation Against Cost (CV) Figure 4 Weekly Analysis Schedule Variance (CV) chart Figure 5 Cumulative Analysis Schedule Variance (CV) graph Figure 6 Weekly Analysis Schedule Variance (BV) chart Figure 7 Cumulative Analysis Schedule Variance (BV) graph Figure 9Weekly Analysis Cost Performance Index (CPI) chart For manage and supervise this activity so that it can run smoothly, on time, right quality and cost, as well as orderly administration in accordance with applicable regulations/related to work.In this regard, the author is interested in compiling a final project entitled "Time and Cost Control for the Construction of Sedimen Trap Check Dam in Bandung and Sumedang Regencies".The objectives of this research were: (1) To find out the time deviation in Construction Work Projects Sediment Trap Check DAM Cikeruh area, Sumedang, West Java.(2) Knowing deviations from costs in Construction Work Projects Sediment Trap Check DAM Cikeruh area, Sumedang, West Java.(3) Find out the deviations from the expenditure budget in Construction Work Projects Sediment Trap Check DAM Cikeruh area, Sumedang, West Java.(4) Knowing the cost and time performance index on Construction Work Projects Sediment Trap Check DAM Cikeruh area, Sumedang, West Java.Information about the System and Existence of the Project.Data analysis method is done in a wayBudget At Completition and the Earned Value Method Page 317 Asian Journal of Engineering, Social and Health Volume 2, No. 5 May 2023 and ACWP obtained from project accounting data.Project cost control analysis is carried out using the indicators Cost Variance (CV), Cost Performance Index (CPI), Estimate To Complete (ETC), and Estimate At Completion (EAC).