Analysis of Project Acceleration Implementation Using the CPM and PERT at Lettu Imam Building

. Target kegiatan


INTRODUCTION
The fundamental obstacles to building and maintaining the infrastructural networks necessary for economic stability are being addressed by Indonesia. Infrastructure network management and administration are becoming increasingly concerned due to deteriorating infrastructures, rising costs, resource scarcity, productivity, rapid regional expansion, environmental concerns, and expansive growth. [1].
To accomplish the specified goals, the project combines a variety of resources (labor, finances, tools, infrastructure, and support services) under a single company. [2].
A project consists of several transient tasks with time constraints, precise resource allocations, and predetermined goals. The task that will help the company is defined and chosen as part of the project. Time and money constraints place a restriction on project activity. Projects have a start and conclusion point, are nonroutine, multi-activity with different intensities, have short cycles, and are subject to finance limits. [3].
Projects are temporary activities that aim to produce products with clearly defined criteria with limited resource allocation and lasting within a certain period, where the costs required to complete a project consist of direct and indirect costs. A large number of activities in a project and the relationship between activities in a complex project causes the need for a project implementation scheduling plan so that in project implementation, there is no difficulty in meeting the agreed conditions in terms of the project cost, project duration, and quality of the final result. Scheduling for complex projects is not easy, requires special skills, and requires time and effort. Optimal scheduling allows optimal cost and duration to be obtained [4].
The more activities whose completion is not by the initial plan, the greater the total time required to complete the project. Therefore, sound planning is needed in compiling the duration of each work, the order of work items, and determining each item that should not be delayed [5] .
However, in the implementation process, conditions in the field are often unpredictable, so the possibility of delays is also high. In this case, it is known that the construction process of this building is experiencing delays. Where the construction should have started in May but in fact, it was carried out in June. As a consequence, the completion of this project was delayed, the project was required to be completed in November, but this construction project was completed in December. In addition, this project also found a volume shortage due to a lack of time. This volume deficiency was in the ceiling painting work, which resulted in the contractor being required to pay a fine of 89 million rupiahs.
There are impacts that often occur due to delays in construction projects, namely additional costs, where the amount is greater than the costs estimated at the beginning of the project, additional time required to finish the project, late payments, rescheduling of the specified time due to disruptions. and problems that arise, the impact on the company's reputation, as well as the loss of productivity and labor efficiency in completing projects [6].
Another study, using a combination of CPM and PERT methods, is to find the critical path and calculate the probability that it can be achieved. However, in this study, a combination of CPM and PERT is used to find the critical path and determine the probability of completion within the desired time. So that it can be adjusted according to needs or by the conditions of the completion time, bearing in mind that events in the field are often unexpected. This study uses the help of GeoGebra software to determine normal distribution values so that the results obtained will be more accurate than the normal distribution tables commonly used, considering that normal distribution tables have limited data presentation. In addition, the fundamental difference from previous research is the difference in research locations which have their own challenges and constraints.
The Critical Path Method (CPM) network is used for projects that are repetitive in nature or for projects for which it is possible to predict costs and the amount of time needed to complete each activity with reasonable precision. The Critical Path Method (CPM), for instance, is advantageous for building projects. However, it is not appropriate for initiatives involving research and development [7].
A method of management science for project planning and control is program evaluation and review. Instead of making a schedule, PERT's goal is to examine the project network. In the application, PERT uses three times estimations that are optimistic, most likely, and pessimistic to deal with the durational uncertainty [8].
The Project Evaluation Review Technic (PERT) method uses a probabilistic approach, while the Critical Path Method (CPM) uses a deterministic approach for project scheduling and evaluation. Despite a little difference, the CPM-PERT approach can be used to analyze project duration because it serves the same purpose [9].

RESEARCH METHOD
The stages of this research are illustrated by the flow chart as follows:

Type of Research
This type of research method is quantitative. The method carried out is in the form of alternative planning of the optimal duration of the project using the CPM and PERT method based on data obtained from direct observations and interview in the field.
The object of this research is one of the Pasuruan Regency Organisasi Perangkat Daerah (OPD) Office Building named Lettu Imam Building and the subject of this research is project time control by the CPM and PERT method.

Research Variable
The purpose of this study was to determine the time of acceleration of the implementation of the construction of the Lettu Imam Building so that the variables in this study were focused on the time of implementation of project activities.

Data Analysis Method
Research must be carried out systematically with a clear and orderly sequence to obtain the expected goals and results. Therefore, the implementation of this research is divided into several stages as follows: 1. Literature Study Before starting the research, a literature study was conducted to deepen knowledge about the topic by reading several books, lecture materials, journals, and references related to the research topic.
2. Data Collection At this stage, the project data collection needed to support the research was carried out. The data needed is the schedule of project activities for the Lettu Imam Building. These data were obtained from PT. Cipta Karya Multi Teknik who worked on the project.
The data was collected through direct surveys at the project site. Interviews were conducted directly with several project experts. The data is supporting data related to constructing the Lettu Imam Building construction project and some literature. The data required are as follows: 1) S Curve 2) Budget Plan

3) Shop Drawing 3. Determining Research Object
To determine the object of research, it is necessary to collect data. Then identify the problem to be studied. In this study, the object in question is the acceleration of the duration of the implementation of the Lettu Imam Building construction activity.

Research Implementation
The secondary data are collected and then researched for the acceleration of duration planning on the Lettu Imam Building construction project using the CPM and PERT. The estimated completion time of a project can be determined by: a. Single duration estimate (CPM approach). b. Triple duration estimate, which is a time estimation method based on three kinds of duration (PERT approach).

Critical Path Method (CPM)
In the process of identifying the critical path, some terminology and calculation formulas are known as follows: a a. New activity can be started when the activity that precedes it has been completed, excepting for the initial activity. b. The earliest completion time of an activity is the same as the earliest start time, plus the period of the activity concerned.
(1) c. The earliest start time of an activity is equal to the earliest finish time of the preceding activity with the most earliest start times when there are two or more prior activities that combine. The backward computation is intended to determine the latest time or date that each activity can start and end without delaying the overall project completion period, which has been generated from the forward count. The countdown begins from a network's far right (last day of project completion). The following are the rules or rules for compiling a network in a countdown: a.
A bold line indicates the presence of the critical path. If the network has only one starting point (initial node) and one endpoint (terminal node), then the critical path also means the path with the longest completion times, and that amount of time is the fastest project time. Sometimes find more than one critical path in a network. The total float can be calculated by formula as follows: (3) Total Float (TF) indicates how long an activity may be delayed so as not to affect the project completion time. The duration of an activity can be written as the amount of time obtained if all previous activities started as early as possible and subsequent activities started as late as possible. This float is owned by all activities that are on the path in question.

Total Float Calculation
Total Float (TF) indicates how long an activity may be delayed so as not to affect the project completion time. The duration of an activity can be written as the amount of time obtained if all previous activities started as early as possible and subsequent activities started as late as possible. This float is owned by all activities that are on the path in question. The following is the calculation procedure for work A2 in the table above. Through the calculations, it is known that the critical path is in activity A1 -A2 -A3 -B1 -C1 -C2 -C3 -C4 -C5 -C6 -C7 -C8 -C9 -D1 or because these activities have no slack time or total float (TF) = 0.

Network Diagram Planning
The initial step in processing data with this method is to plan a network diagram. Network diagrams can present activities, the duration of each activity, the sequence of activities, and the linkages between activities to identify which activities are on the critical path easily. Red boxes and arrows indicate critical activities in a project.

The Value of ta, tb and tm
Based on the results of interviews with the contractor for the Lettu Imam Building construction project, the values for ta, tb and tm are presented in the following table.

Activity Time (Te), Standard Deviation (S), and Activity Variation (Ve) Calculation
After determining the implementation time with the 3-time estimates above, the expected timeframe (Te) and the probability of successful project scheduling can be determined with detailed calculations below. The following is the calculation procedure for work A1 in the

Probability of Achieving Target Schedule
After getting the total value of Te and the value of S, then determine the probability value. To make it easier to find the probability value, apart from using the normal distribution table, it can also be calculated with the help of the GeoGebra software. Based on the results of probability calculations using geogebra software, the probability value that the project can be completed in 158 days is 0.1056 or equal to 10.56%. The probability of the desired duration of work can be seen in the following table:

CONCLUSION
Based on the results of data processing and the discussion described above, it can be concluded that the network form for the Lettu Imam Building development project lies in the activity Preliminary Work -Concrete Work -Soil Work -Concrete Work -Concrete Work -Masonry Brick and Plaster Work -Wall and Floor Covering Work -Frame and Accessories Work -Roof Work -Ceiling Work -Painting Work -Mechanical and Electrical Work -Sanitation Work -Connection Work (Critical Path). For the optimal time duration for the Lettu Imam Building construction project from the results of research analysis using the PERT method obtained data that to obtain a project completion probability of 89,43% -99,37%, the required duration of project implementation is 162 -164 days.