scholarly journals A Comparative Study on Time-cost Trade-off Approaches within Critical Path Method

2011 ◽  
Vol 11 (6) ◽  
pp. 920-931
Author(s):  
Wakas S. Khalaf ◽  
Leong Wah June ◽  
Mohd Rizam B. Abu Bakar ◽  
Lee Lai Soon
Rekayasa ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
Nailul Izzah

<p>Pada pembangunan proyek perumahan, perencanaan dibutuhkan untuk memperhitungkan berbagai variabel pekerjaan yang menyangkut sumber daya yang terbatas seperti waktu dan biaya. Tujuan dari penelitian ini  adalah mendeskripsikan aktivitas jaringan kerja yang optimal dengan metode <em>Critical Path Method </em>(CPM), perencananaan kelayakan yang optimal dengan metode <em>Program</em><em> </em><em>Evaluation and Review Technique</em> (PERT), dan mendeskripsikan waktu dan biaya proyek yang efisien dengan metode <em>Time Cost Trade Off </em>(TCTO) pada proses pembangunan perumahan. Jalur kritis dari penerapan metode <em>critical path method</em> (CPM) dimulai dari pekerjaan persiapan (A) sampai pekerjaan pagar (AB), tetapi ada satu yang tidak termasuk pada jalur kritis yaitu pekerjaan plafond (H). Pekerjaan tersebut memiliki nilai slack 25, artinya kegiatan tersebut memiliki kelonggaran waktu pengerjaan selama 25 hari. Dari penerapan metode <em>program</em><em> </em><em>evaluation and review technique</em> (PERT), proyek perumahan dapat diselesaikan lebih cepat dari kurun waktu normal selama 555 hari dengan waktu yang diharapkan 547 hari dengan peluang 64,8%. Sedangkan dari penerapan metode <em>time cost trade off</em> (TCTO), efisiensi waktu pengerjaan proyek dengan penambahan pekerja adalah 5,76% dengan selisih percepatan 32 hari kerja dan efisiensi biayanya adalah 0,156% dengan biaya optimal sebesar Rp. 6.753.245.793</p><p>Kata kunci: <em>Critical Path Method</em> (CPM), <em>Program Evaluation and Review Technique</em> (PERT), <em>Time Cost Trade Off</em> (TCTO).<strong> </strong></p><p align="center"><strong> </strong></p><p align="center">Time Exchange Analysis and Cost Using<em> Time Cost Trade Off </em>(TCTO) Method in Housing Development Projects in PT. X</p><p><strong>ABSTRACT</strong></p><p><em>In the construction of housing projects, planning is needed to account for the various work variables involving limited resources such as time and cost order to achieve the stated objectives and achieve the desired results. The purpose of this research is to describe optimal network activity from the application of Critical Path Method (CPM) method, to describe optimal feasibility planning from applying of Program Evaluation and Review Technique (PERT) method, and to describe time and cost of efficient project from application of Time method Cost Trade Off (TCTO) on the housing development process. The critical path from the application of the method of critical path method (CPM) starts from the preparatory work (A) to the fence work (AB), but there is one that is not included in the critical path ie the ceiling work (H). The work has a slack value of 25, meaning that the activity has a working time clearance for 25 days. From the implementation of the evaluation and review technique (PERT) program method, the housing project can be completed faster than the normal time period of 555 days with the expected time 547 days with a chance of 64.8%. While from the time cost trade off (TCTO) method, the time efficiency of project work with the addition of worker is 5.76% with the acceleration difference of 32 working days and the cost efficiency is 0.156% with the optimum cost of Rp.</em><em>6.753.245.793.</em><em></em></p><em>Keywords: Critical Path Method (CPM), Program Evaluation and Review Technique (PERT), Time Cost Trade Off (TCTO). </em>


2018 ◽  
Vol 10 (8) ◽  
pp. 2802 ◽  
Author(s):  
Hongbo Li ◽  
Zhe Xu ◽  
Wenchao Wei

In sustainable project management, time and cost are two critical factors affecting the success of a project. Time/cost trade-offs in projects accelerate the execution of some activities by increasing the amount of non-renewable resources committed to them and therefore shorten the project duration. The discrete time/cost trade-off problem (DTCTP) has been extensively studied during the past 20 years. However, due to its complexity, the DTCTP—especially the DTCTP curve problem (DTCTP-C)—has only been solved for relatively small instances. To the best of our knowledge, there is no computational performance analysis for solving the DTCTP-C on large project instances with up to 500 activities. This paper aims to fill this gap. We present two bi-objective heuristic algorithms for the DTCTP-C where both project duration and cost are minimized. The objective is to obtain a good appropriate efficient set for the large-scale instances. The first algorithm is based on the non-dominated sorting genetic algorithm II (NSGA-II) and uses a specially designed critical path-based crossover operator. The second algorithm is a steepest descent heuristic which generates efficient solutions by iteratively solving the DTCTP with different deadlines. Computational experiments are conducted to validate the proposed algorithms on a large set of randomly generated problem instances.


2019 ◽  
Vol 25 (2) ◽  
pp. 277-299 ◽  
Author(s):  
Mohammad Hossein Haghighi ◽  
Seyed Meysam Mousavi ◽  
Jurgita Antuchevičienė ◽  
Vahid Mohagheghi

This paper proposes a new framework in addressing time-cost trade-off problem (TCTP) under uncertainty. First critical path analysis is carried out based on developing a new interval-valued fuzzy (IVF)-program evaluation and review technique (PERT) approach. Then, non-conformance risks that influence on execution quality of activities are identified and evaluated based on a new approach that considers probability of risk along with impacts on time, cost, and performance. Then, a new mathematical model under IVF uncertainty is presented to decrease project total time while considering time, cost and quality loss cost that is determined in form of rework or modification cost. Finally, the approach categorizes the activities in three groups based on their level of criticality. Outcome of this methodology is a scheduling that addresses time, cost and quality trade-offs in addition to categorizing activities in different groups based on being on the critical path. Therefore, the project manager not only gets a scheduling based on the TCTP with considering quality loss cost but also has a knowledge of activities that require extra attentions. To show the steps of this methodology, an existing application from the literature is adopted and solved.


2019 ◽  
Vol 11 (1) ◽  
pp. 33-40
Author(s):  
Cut Zukhrina Oktaviani ◽  
Ibnu Abbas Majid ◽  
Risdiawati Risdiawati

Construction delays are a common and major concern in most construction projects. Construction project delay can indirectly affect of project performance. Delay resolve method is to schedule crashing with various methods. This crashing planning is done by combining the Critical Path Method (CPM) and Time-Cost Trade-Off (TCTO) method for the minimum cost in crash duration calculation. Project A data is used to be a case studi in crash duration calculation and costs increase. Rescheduling with CPM result project completion time 120 days and after crashing project duration becomes 94 days, there was a reduction 26 days project completion time. Crashing programme are do to 18 activities from 30 critical activies rescheduling with CPM result. Total project costs changes is Rp. 19.923.466,- due working time addition (overtime) to reduce project time with Time Cost Trade Off method. Normal condition project costs is Rp. 985,171,182.52 and after duration crash becomes Rp. 1,005,094,648, -.


EXTRAPOLASI ◽  
2021 ◽  
Vol 17 (1) ◽  
pp. 20-29
Author(s):  
Rizal Rosyid ◽  
Gede Sarya ◽  
Michella Beatrix ◽  
Wateno Oetomo

AbstractTime cost trade off is a schedule compression to get projects that are more profitable in terms of time (duration), costs, and income. The aim is to compress the project to an acceptable duration and minimize the total project cost. The reduction in project duration is done by selecting certain activities. The analysis begins by preparing a network diagram (network diagram) using Microsoft Project. After that the crashing process is done using the addition of workers and additional hours of work contained in the critical path. Next do the calculations with the time cost trade off method to find the value of the crash cost and cost slope contained in the critical path. From the results of the analysis, the normal duration of the project is 639 calendar days after the process of crashing, adding work hours to 622 days and labor to 623 calendar days and the initial project cost of Rp. 250,320,084,731 after the process of crashing activities with an alternative addition to labor obtained a fee of Rp. 250,559,140,422 and additional working hours in the amount of Rp. 252,734,398,495. So that it can be concluded with the time cost trade off method there is a reduction in the duration and increase in costs.AbstrakTime cost trade off merupakan kompresi jadwal untuk mendapatkan proyek yang lebih menguntungkan dari segi waktu (durasi), biaya, dan pendapatan. Tujuannya adalah memampatkan proyek dengan durasi yang dapat diterima dan meminimalisasi biaya total proyek. Pengurangan durasi proyek dilakukan dengan memilih aktivitas tertentu. Analisa dimulai dengan melakukan penyusunan jaringan kerja ( network diagram ) dengan menggunakan microsoft project. Setelah itu dilakukan proses crashing menggunakan penambahan pekerja dan penambahan jam kerja yang terdapat pada jalur kritis. Selanjutnya melakukan perhitungan dengan metode time cost trade off untuk mencari nilai crash cost dan cost slope yang terdapat pada jalur kritis. Dari hasil analisa yang dilakukan diperoleh durasi proyek normal 639 hari kalender setelah dilakukan proses crashing kegiatan penambahan jam kerja menjadi 622 Hari dan tenaga kerja menjadi 623 hari kalender dan biaya proyek awal sebesar Rp. 250.320.084.731 setelah dilakukan proses crashing kegiatan dengan alternatif penambahan tenaga kerja diperoleh biaya sebesar Rp. 250.559.140.422 dan penambahan jam kerja sebesar Rp. 252,734,398,495. Sehingga dapat disimpulkan dengan metode time cost trade off terjadi pengurangan durasi dan peningkatan biaya. 


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