The Project Scheduling Game (PSG): Simulating Time/Cost Trade-Offs in Projects

2005 ◽  
Vol 36 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Mario Vanhoucke ◽  
Ann Vereecke ◽  
Paul Gemmel

The Project Scheduling Game is an IT-supported simulation game that illustrates the complexity of scheduling a real-life project. The project is based on a sequence of activities for a large real-life project at the Vlaamse Maatschappij voor Watervoorziening, which aims at the expansion of the capacity to produce purified water. The basic problem type that we use in the game has been described in the literature as a CPM (critical path method) network problem, and focuses on the time/cost relationship in each activity of the project. Indeed, by allocating resources to a particular activity, the manager decides about the duration and corresponding cost of each network activity. The manager schedules the project with the negotiated project deadline in mind, focusing on the minimization of the total project cost.

Organizacija ◽  
2008 ◽  
Vol 41 (4) ◽  
pp. 153-158
Author(s):  
Uroš Klanšek ◽  
Mirko Pšunder

Cost Optimal Project SchedulingThis paper presents the cost optimal project scheduling. The optimization was performed by the nonlinear programming approach, NLP. The nonlinear total project cost objective function is subjected to the rigorous system of the activity precedence relationship constraints, the activity duration constraints and the project duration constraints. The set of activity precedence relationship constraints was defined to comprise Finish-to-Start, Start-to-Start, Start-to-Finish and Finish-to-Finish precedence relationships between activities. The activity duration constraints determine relationships between minimum, maximum and possible duration of the project activities. The project duration constraints define the maximum feasible project duration. A numerical example is presented at the end of the paper in order to present the applicability of the proposed approach.


Author(s):  
Dinda Fardila ◽  
Nuur Robbyatul Adawyah

ABSTRACT                                                                         In the construction of a construction project, there are three main elements: time efficiency, minimal costs, and appropriate quality. This study aims to calculate changes in the cost and time of project implementation with variations in overtime and additional workforce. Data analysis using Microsoft Project 2010 program and Time-Cost Trade-Off method. The results of this study indicate that (1) the optimum time and costs due to overtime are obtained at the project age of 235 working days with a total project cost of IDR 8,438,038,832 with a project time efficiency of 5 days (2.13%) and a project cost efficiency of IDR 3.559,695 (0.042%). (2) The optimum time and cost due to the addition of labor is the best choice with the results obtained at the project age of 226 working days with a total project cost of IDR 8,429,832,759 with a project time efficiency of 14 days (6.19%) and cost-efficiency. project amounting to Rp. 11,779,674 (0.14%). ABSTRAKDalam pelaksanaan pembangunan suatu proyek konstruksi, terdapat tiga unsur utama yaitu waktu yang efisien, biaya minimal dan mutu yang sesuai. Tujuan dari penelitian ini adalah menghitung perubahan biaya dan waktu pelaksanaan proyek dengan variasi lembur dan penambahan tenaga kerja. Analisis data menggunakan program Microsoft Project 2010 dan metode Time Cost Trade Off. Hasil penelitian ini menunjukkan bahwa (1) Waktu dan biaya optimum akibat lembur didapat pada umur proyek 235 hari kerja dengan total biaya proyek sebesar Rp8.438.038.832 dengan efisiensi waktu proyek sebanyak 5 hari (2,13%) dan efisiensi biaya proyek sebesar Rp3.559.695 (0,042%). (2) Waktu dan biaya optimum akibat penambahan tenaga kerja menjadi pilihan terbaik dengan hasil yang didapat pada umur proyek 226 hari kerja dengan total biaya proyek sebesar Rp8.429.832.759 dengan efisiensi waktu proyek sebanyak 14 hari (6,19%) dan efisiensi biaya proyek sebesar Rp11.779.674 (0,14%).


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>


2012 ◽  
Vol 2 (2) ◽  
pp. 91-101 ◽  
Author(s):  
V. Sireesha ◽  
N. Ravi Shankar ◽  
K. Srinivasa Rao ◽  
P. Phani Bushan Rao

In this paper, the authors propose a new method to compute the fuzzy latest times and float times of activities for a project scheduling problem with fuzzy activity times. The authors have considered LR fuzzy numbers to represent the activity times. As the data of the problem are LR fuzzy numbers, the authors have shown that the results are also in terms of LR fuzzy numbers. Total float time of each activity can be found by this method without using the forward pass and backward pass computations. The authors use an example to illustrate the method. This paper shows the advantages of this method over the existing methods with great clarity. The proposed method illustrates its application to fuzzy critical path problems occurring in real life situations.


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, -.


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