Continuous Adjustments and the Reality Test in Managing Complex Projects

A dependent project evaluation and review technique: A Bayesian network approach

The Program Evaluation and Review Technique (PERT) is a popular scheduling technique that takes advantage of the Beta distribution to present uncertainty in activity durations. This study presents an advanced PERT method with an improved Bayesian updating and improved assumed prior distributions, which better represent real-world projects. The method is backed with detailed mathematical proofs and derivations for a solid theoretical foundation. A numerical case study involving a 30-floor building construction project is used to compare the performance of traditional PERT, the Beta-improved Bayesian PERT, and the Log-Normal Bayesian PERT methods. In the example, the activities considered are Formwork, Rebar and Construction, Masonry, Mechanical-Electrical-Plumbing (MEP), and Finishing, which are the main activities in a construction project. The results show that the Beta-improved and the Log-Normal distributions are constructed successfully in the models with converging variance – an observation that delineates the uncertainty reduced along a real project’s course. With enhanced functions, the PERT method can be utilized to support project decision-makers in scheduling and managing complex projects in reality.

This study discusses the importance of scheduling in construction projects, particularly the application of the Precedence Diagram Method (PDM) and the Program Evaluation and Review Technique (PERT) to enhance time efficiency and identify critical activities. Project scheduling is a key element that ensures the project progresses according to plan and is completed on time. PDM serves to illustrate the sequence and interrelationships between activities through node representation, allowing the identification of the critical path. Meanwhile, PERT uses a probabilistic approach with three time estimates to anticipate variations and uncertainties in activity durations. A case study of a health center construction project in Banteang Regency demonstrates that the application of PDM and PERT, compared to the S-curve method, can optimize resource allocation, minimize the risk of delays, and ensure scheduling efficiency. With the support of software like Microsoft Project, the implementation of these two methods is expected to improve project control and ensure timely completion. Abstrak Penelitian ini membahas pentingnya penjadwalan dalam proyek konstruksi, khususnya penerapan metode Precedence Diagram Method (PDM) dan Program Evaluation and Review Technique (PERT) untuk meningkatkan efisiensi waktu dan identifikasi kegiatan kritis. Penjadwalan proyek merupakan elemen kunci yang memastikan proyek berjalan sesuai rencana dan selesai tepat waktu. PDM berfungsi untuk menggambarkan urutan dan keterkaitan antar kegiatan melalui representasi node, sehingga memungkinkan identifikasi jalur kritis. Sementara itu, PERT menggunakan pendekatan probabilistik dengan tiga estimasi waktu untuk mengantisipasi variasi dan ketidakpastian dalam durasi kegiatan. Studi kasus pembangunan puskesmas di Kabupaten Banteang menunjukkan bahwa penerapan metode PDM dan PERT, dibandingkan dengan metode kurva-S, dapat mengoptimalkan alokasi sumber daya, meminimalisir risiko penundaan, dan memastikan efisiensi penjadwalan. Dengan dukungan software seperti Microsoft Project, penerapan kedua metode ini diharapkan dapat meningkatkan pengendalian proyek dan memastikan penyelesaian yang tepat waktu.

The video game industry has grown exponentially over the past few decades, becoming a dominant force in the global entertainment sector. Despite its rapid growth, the game development process remains highly complex and distinct from traditional software development, requiring a creative and agile approach. This paper addresses the challenge of inaccurate time estimation in game development projects, which often results from the inherent uncertainty inherent in the iterative and creative nature of the industry. This study integrates the Critical Path Method (CPM) and the Program Evaluation and Review Technique (PERT) with the Rayleigh distribution to improve the accuracy of time estimation in the context of high uncertainty. Data from a completed game development project by an Indonesian game company is analyzed using this methodology. The results show that the Rayleigh-PERT model, with 70% confidence and an expert quality estimate of 0,3, provides the most accurate time estimation, showing only a 4,26% deviation from actual project performance, compared to 20% for CPM and 15,2% for traditional PERT. This research contributes to improving project management in the video game industry by incorporating uncertainty into time estimation, offering more realistic schedules for game development projects, and improving overall project execution.

Although Program Evaluation and Review Technique(PERT) has been applied widely in the planning and control of the project progress, there are some deficiencies, for example, the accuracy of the estimated activity duration is not high, the distribution pattern of the duration variable is single, the calculation result of the project completion probability is slightly larger and so on. Based on present research results, this article proposes using Monte Carlo simulation method to simulate varieties of distribution situations of the activity duration with Crystal Ball and Excel tools, and calculate the completion time and the probability distribution of the project according to the Critical Path Method(CPM). In the last, this article verifies the effectiveness and the convenience of this method by an example. Because of abandoning assumptions of the PERT, therefore the random simulation model has more stronger adaptability and credibility than the traditional PERT. Taking advantage of Crystal Ball and Excel tools, the project progress managers can easily realize the random simulation and calculation of the large-scale complex projects, then guarantee the successful completion of the project and reduce the risk of duration delay.

Residential construction projects can have many risks and uncertainties that can affect their completion time. To ensure a residential construction project is completed on time, accurate duration estimates are required for each activity. The deterministic duration Critical Path Method (CPM) is extensively used in construction project scheduling. However, this method may not always yield a realistic schedule as it uses only one duration estimation for each activity. As an alternative, this study uses the Program Evaluation and Review Technique (PERT) which utilizes three duration estimates, and the Monte Carlo Simulation (MCS) which simulates the duration 5000 times. A house construction project with 24 activities was analyzed using CPM which yielded 63 days completion time. The project was then analyzed using PERT and MCS. PERT and MCS calculations found that to complete the project with a 95% level of confidence the project needed 70 and 79 days, respectively. The findings of this study indicate that PERT and MCS can assist project managers in creating a more realistic project schedule by considering the risks and uncertainties inherent in a construction project.

This study examines the comparison of PERT (Program Evaluation and Review Technique) and CPM (Critical Path Method) in time management for construction projects through a case study of a 21-story high-rise building project in Yogyakarta. The research is motivated by the need for effective time management in construction projects to avoid delays that may escalate costs and disrupt project execution. The objectives are to determine the estimated duration for completing the building’s structural work, compare the differences between the initial schedule and the results of PERT and CPM analyses. The study employs a case study approach, with primary data collected through direct interviews with project stakeholders regarding activity durations and predecessors, as well as secondary data from project documentation, including schedules and structural drawings. Data analysis involves applying PERT calculations using three-time estimates (optimistic, most likely, and pessimistic) and identifying critical paths through CPM. Data processing and network diagram visualization are conducted using a project management software to comprehensively map critical and non-critical project activities. Results indicate that the CPM method predicts a project duration of 419 days, 237 days shorter than the initial schedule, while the PERT method estimates 580 days, 76 days shorter than the original timeline, with an 82.98% probability of timely completion.

The project scheduling establish the time sequence of various activities which has a certain time limit, this means that the project must be completed before or exactly at the specified time. The delay effect and result in delays to the completion of the overall project. The purpose of study is to analyze the scheduling of the project to find out how long a project can be completed, determine the critical path as well as optimize the time of execution of the project. Research methods used for the project implementation analysis of Clubhouse building construction using critical path method (CPM) and program evaluation and review technique (PERT). Results of the discussion and calculations obtained that the completion of the project still in accordance with the schedule that has been determained, with the critical path method (CPM) is 321 days, and the program evaluation and review technique (PERT), time most quickly resolved is 312 days (value of Z= 0,22%), the slowest time is 339 days (value of Z= 99,87%) and the most probable time is 325 days (value of Z= 49,20%). Be aware of the activities which constitute the critical path is the activities: A, B1, B2, B3, B4, C1, C2, C3, C4, C6, C5, C7, C8, D, and obtained the optimization of project completion time with the CPM method is 48 days, PERT method, time most quickly is 57 days,the slowest time is 30 days, and the most possible time is 44 days.

Program Evaluation and Review Technique (PERT) is a method of planning work, comparing status with schedule, and evaluating progress at all levels of management in order to better control a major, complex, engineering project. PERT/COST adds control of manpower and funds. Three time estimates—optimistic, most likely, and pessimistic—are combined to obtain an expected time for completing each activity. The PERT network shows interdependencies of activities. An important result of the PERT calculations is the determination of the critical and slack paths of the network.

The path float use in the network is an effective method used to cope with various uncertainties existing within the construction. However, the current path float calculating method may bring misleading information to the managers on site and then cause project duration risk in the construction. The purpose of this paper is to present a new method, which calculates the noncritical path float in the program evaluation and review technique (PERT), to copy with the uncertainties within the network implementation, and to reduce the misleading information. An example network was analyzed with the new method, the results showed the consistent path float under required completion probability and required duration. The new path float concept will bring useful planning information to the managers and the planners in the construction.

RPERT: Repetitive-Projects Evaluation and Review Technique

Project Control Based on a Mutual Application of Pert and Earned Value Management Methods

Proyek konstruksi memiliki tahapan dalam melaksanakan proses pekerjaan yang sulit dan saling ketergantungan antara satu dengan yang lainnya, maka dari itu pentingnya melakukan penjadwalan guna mengatur arah jalannya suatu proyek agar sesuai yang telah direncanakan guna meminimalisir terjadinya keterlambatan. Penelitian ini bertujuan untuk: (1) mengetahui berapa lama waktu pelaksanaan proyek dengan menggunakan metode PERT pada Pembangunan Gedung DINDIKBUD dan (2) memperoleh durasi kemungkinan (probability) penyelesaian proyek dengan tepat waktu. Pengumpulan data diperoleh dari DPUPR (Dinas Pekerjaan Umum dan Penataan Ruang) Kabupaten Purworejo. Dalam menganalisis data yang diperlukan adalah data primer dan data sekunder. Data primer berupa Kurva S dan data sekunder berupa wawancara dengan staff ahli, pada penelitian ini menggunakan metode PERT (Program Evaluation and Review Technique). PERT merupakan metode untuk menghadapi situasi waktu yang tidak pasti pada suatu kegiatan, maka digunakan pendekatan yang menganggap kurun waktu kegiatan tergantung pada banyak faktor dan variasi sehingga dalam memperkirakan durasi suatu kegiatan dibutuhkan tiga angka estimasi yaitu optimis (a), pesimis (b) dan waktu yang paling mungkin (m). Pengukuran ketidakpastian diukur menggunakan Devian Standar dan Varians. Analisis metode PERT menggunakan bantuan software Ms. Excel didapatkan hasil bahwa pembangunan Gedung DINDIKBUD Kabupaten Purworejo tahap II yaitu membutuhkan waktu pelaksanaan proyek selama 172 hari dengan kemungkinan (probability) proyek untuk diselesaikan sebesar 92,51%. Pada tahap III diperlukan waktu pelaksanaan proyek selama 174 hari dengan kemungkinan (probability) proyek untuk diselesaikan sebesar 88,30%.

A Dynamic Operations Research Framework for Military Logistics and Resource Allocation Under Uncertainty: A War Simulation Case Study

At present, EPC project is one of hiring contracts for engineering design and construction of petrochemical plant. EPC project management is management under the lump-sum contract or stipulated sum contract of which the owner has essentially assigned all the risks to the contractor, who in turn can be expected to ask for a higher markup to take care of unforeseen contingencies. Generally, complexities of project activity are the main factor in project management. Therefore, effective project scheduling is the important method to reduce cost and time. The Program Evaluation and Review Technique (PERT) is basically a project scheduling management and control tool are widely used for planning and coordinating each activity in large-scale project. The Critical Path Method (CPM) is used extensively to find the longest path in the network diagram or the shortest duration in which the project can be completed. The researcher has aimed to apply PERT and CPM with simulation software add-in Crystal Ball in MS Excel to develop the optimal method for increasing certainty of project finished and reducing time of complexities project duration. To minimize project duration, overall monthly project management cost will be decreased. The finding of this paper showed that using PERT and CPM applied with simulation software add-in Crystal Ball in MS Excel in scheduling project could minimize project duration from 356 days to 312 days and maximize certainty of project finished from 24.49% to approach 100%.