Factors Affecting the Implementation of Green Procurement in Indonesia Construction Industry

A construction industry is often described as inefficient, irresponsible towards environment and society. This research aimed to analyze the factors affecting the implementation of green procurement in Indonesia construction industry. The research project specifically focuses on a construction material procurement. For this purpose, 26 factors were identified and project managers who worked on construction companies with large grade of national / international scales belonging to the association of construction in Surabaya were interviewed. The relative importance on these factors were quantified by Relative Importance Index and Confidence Interval. The result showed that the factors affecting implementation of green procurement in Indonesia construction industry were requirement document (contract) and cost efficient from energy and waste saving

Energy Efficiency of Cooling Load through The Glass Facade of Office Buildings in Surabaya

The aims of this article is to obtain an alternative type of glass on the envelope buildings of full glass on all surface envelope, cost of glazed facades and to obtain energy efficiency of cooling load through the glass facade of office buildings in Surabaya. The shape of the building in this article uses a simulation of regular form (squares) and differences in building orientation. The calculation method is uses the OTTV method (Overall Thermal Transfer Value) for the value of heat gain through the building envelope and the CLTD method (Cooling Load Temperature Difference) to calculate the cooling load affected by the glass facade. The results obtained in this article simulation show that the most efficient value is double glazing with using SC ≤ 1.9 and U value glass ≤ 2.6 W / m2K, so that the energy efficiency of the cooling load obtained can decrease until 6%. The savings were obtained at the value of OTTV is 25.60 W/m2 with the price of glass facade in the amount of Rp. 4,005,333/m

Optimasi (Equal) Site Layout Menggunakan Multi-Objectives Function Pada Proyek A

Pada setiap proyek konstruksi,selalu menggunakan site facilities untuk menunjang kinerja dalam proyek. Jenis site facilities ini tidaklah sama pada setiap proyek karena masing – masing proyek memiliki karakteristik,metode,dan lahan yang berbeda. Tata letak site facilities tersebut harus di atur karena memiliki dampak terhadap waktu dan biaya pengerjaan proyek. Pada penelitian sebelumnya,untuk mengoptimasi site layout digunakan single objective function dan jarak perjalanan hanya diukur secara horizontal. Berbeda dengan penelitian ini yang menggunakan multi-objectives function yaitu Traveling Distance dan Safety Index dan jarak perjalanan yang diukur secara vertikal dan horizontal. Untuk mendapatkan site layout yang optimal,maka langkah yang dilakukan yaitu meminimalkan traveling distance dan safety index. Dari 6 skenario maka didapat hasil traveling distance paling minimum yaitu pada skenario 6 dengan nilai sebesar 119.754,9  atau mengalami penurunan nilai sebesar 9,91% bila dibandingkan dengan kondisi awal. Sedangkan nilai safety index paling minimum yakni pada skenario 4 dengan nilai Sebesar 3.149,84 atau mengalami penurunan sebesar 5,96% bila dibandingkan dengan kondisi awa

The Cultural Differences influences on Knowledge Sharing Activities in Construction Project Collaboration

In the last decades construction activity has been heavily criticized for its productivity and performance in relation to cultural differences. There have been several studies indicated that the cultural diversity influence the knowledge of the organization, and that result in barriers in knowledge sharing in the multicultural organization. The knowledge spreading manners affected by the cultural in organization due to ethnic, cities, sexual category, local culture, which that might lower level of the knowledge spreading in organization . Therefore, a research study is developed in order to assess the influences of cultural differences on the activity of knowledge distribution in organization project and to determine of extend of the cultural differences to obstacle the individual to share their knowledge within the organization or with other members of the organization and how is that leads to decrease the project’s performance. For seeking to achieve the aims of the study a survey questionnaire was used to gather data. System dynamic simulation is utilized to interpret the collected data in order to achieve meaningful information. The results proven that cultural difference is one of the major problems that impact the project performance negatively in the construction industry since it is verified that the cultural difference impacts the knowledge flow among the employees in the construction project which that strongly affects the outcome of the projects and that also leads to decrease the productivity of the project. In addition, the respondents also agree that cultural differences cause unsuccessful safety system in the construction projects. Therefore, the cultural differences should be given careful attention to ensure better project performance

Optimasi Waktu dan Biaya (Time Cost Trade Off - TCTO) Menggunakan Particle Swarm Optimization (PSO)

Pada Proyek Pembangunan Jalur Ganda Jalan Ka Lintas Selatan Jawa Km 49+500 Sd Km 52+500 Antara Mojokerto Solo (Paket JGMS-9) mengalami keterlambatan dikarenakan shopdrawing pengerjaan proyek belum disetujui. Akibat hal tersebut, perlu dilakukan optimasi percepatan waktu untuk mengejar keterlambatan dan mengestimasi pertambahan biayanya. Tugas akhir ini bertujuan untuk mereduksi keterlambatan penyelesaian proyek dengan mempercepat waktu penyelesaian proyek dan dengan biaya seminimal mungkin. Untuk mempercepat durasi proyek akan diterapkan metode Time Cost Trade Off (TCTO). Pada tugas akhir ini Data yang digunakan adalah data sekunder (Schedule, kurva S dan produktivitas pekerja) dan data primer. Optimasi metaheuristic, Particle Swarm Optimization (PSO), digunakan untuk mengoptimalkan pertukaran waktu dan biaya (Time Cost Trade off). algoritma dikerjakan menggunakan program bantu MatLab™. Tahapan penelitian dilakukan dengan menentukan objective function model PSO, men-generate particle dan menentukan velocity dari partikel. Simulasi dilakukan dengan melakukan 1000 kali iterasi. Untuk validasi model, dilakukan perhitungan TCTO secara matematis (manual) kemudian hasilnya dibandingkan dengan luaran PSO. Hasil penelitian menunjukkan bahwa, durasi normal pada pekerjaan jembatan adalah 302 hari dengan biaya normal sebesar Rp. 23.036.343.652. Durasi percepatan proyek setelah dilakukan analisa Time Cost Trade Off (TCTO) dengan menggunakan metode matematis adalah 287 hari dengan biaya percepatan Rp. 28.365.575.129. Durasi percepatan proyek setelah dilakukan analisa Time Cost Trade Off (TCTO) dengan menggunakan Particle Swarm Optimization (PSO) adalah 287 hari dengan biaya percepatan Rp. 28.464.546.260. Dari hasil tersebut terlihat bahwa hasil analisis matematis dan analisis metaheuristik memberikan hasil yang sama, dengan perbedaan 0.001%. Oleh karena itu, model PSO ini dapat diterapkan untuk mengoptimasi waktu dan biaya proyek

An Analysis of Contractor Satisfaction on Owner Team Performance in Construction Projects (Case Study: Construction Projects in ITS)

Subjective performance measurements have been developed on construction projects of various key stakeholders such as contractors, designers and consultants. These approaches are usually related to owner satisfaction, customer satisfaction, occupant satisfaction but very rarely consider contractor satisfaction. The performance of the contractor and owner are interdependent, and their interactions fundamentally determine the overall project performance. This research aims to analyze the level of contractor satisfaction with the team owner’s performance which in the end to improve the improvement (Continuous Improvement) where there are indicators of team’ owner performance that needs attention to be improved and improved and those that need to be maintained. Owner performance indicators include the owner’s understanding of project needs, finances, decision-making, management, adequate support for contractors, client attitudes, clarity of client/owner commitment goals, and the working relationship of the owner and contractor. These indicators were obtained from literature and interviews with practitioners. These indicators are then developed to improve the existing conceptual framework. The satisfaction is measured using the Customer Satisfaction Index (CSI) and priority variables that need to be improved are analyzed by the Importance Performance Analysis (IPA) method. The results of this study indicate the level of contractor satisfaction with the performance of the team owner from CSI calculations at the level of satisfaction. Meanwhile the results of the IPA show that financial indicators, one sub-indicator of support for contractors and one sub-indicator of the attitude of the owner must be improved. Keywords: Contractor satisfaction, Owner performance, Customer Satisfaction Index (CSI), Importance Performance Analysis (IPA)

Life Cycle Cost Structure of a Government Office Green Building – Case of the Ministry of Public Works and Housing Main Building

One of the efforts to reduce the large impact of building sectors on the environment is the concept of environmentally friendly building known as green buildings. With the increasing global interest in this concept, green building development in Indonesia was also expected to increase. Cost is one of the most important focus for promoting green buildings, so it is necessary to conduct a cost analysis of a green building to provide a clearer understanding of the life cycle cost structure of a green building in its life cycle as a study to develop the knowledge of Infrastructure Asset Management. In this study data related to the cost component of the government office green building was identified to determine the overall cost of the building from the beginning of its construction until recent year, which can be described as: Initial Cost, Operation and Maintenance Cost, and Energy Cost. The result of this study finds out that during 8 year period of its lifetime the total building expenditure is Rp 483.649.711.849,00 and the life cycle cost structure percentage are: initial cost 43,94%, operation and maintenance cost 39,48%, and energy cost 16,57%. The total energy cost saving is Rp 28.072.536.738,00

The Cultural Differences Influences on Knowledge Sharing Activities in Construction Project Collaboration

In the last decades construction activity has been heavily criticized for its productivity and performance in relation to cultural differences. There have been several studies indicated that the cultural diversity influence the knowledge of the organization, and that result in barriers in knowledge sharing in the multicultural organization. The knowledge spreading manners affected by the cultural in organization due to ethnic, cities, sexual category, local culture, which that might lower level of the knowledge spreading in organization . Therefore, a research study is developed in order to assess the influences of cultural differences on the activity of knowledge distribution in organization project and to determine of extend of the cultural differences to obstacle the individual to share their knowledge within the organization or with other members of the organization and how is that leads to decrease the project's performance. For seeking to achieve the aims of the study a survey questionnaire was used to gather data. System dynamic simulation is utilized to interpret the collected data in order to achieve meaningful information. The results proven that cultural difference is one of the major problems that impact the project performance negatively in the construction industry since it is verified that the cultural difference impacts the knowledge flow among the employees in the construction project which that strongly affects the outcome of the projects and that also leads to decrease the productivity of the project. In addition, the respondents also agree that cultural differences cause unsuccessful safety system in the construction projects. Therefore, the cultural differences should be given careful attention to ensure better project performance

Non Linear EVM based on Support Vector Regression Growth Model for Predicting Project Completion Time

Earned Value Management (EVM) is a method used to monitor and to predict project completion time. This method uses a linear approach in predicting project time completion. Unfortunately, most of the projects run in dynamic environments with complex characteristics, causing project progress to require a non-linear approach. That is why the use of EVM in monitoring and predicting non-linear project completion time is less effective. This study proposes a more realistic alternative approach using non-Linear EVM based on the Support Vector Regression (SVR) - Growth Model. The SVR-growth model is used to accommodate the non-linear progress of the project, while the EVM is used to represent the predicted results of the project completion time. For model validation, 5 data on oil and gas field development construction projects in Jawa, Bali and Nusa Tenggara Regions were used as case studies. The results of this study indicate that the results of project completion time prediction using the SVR-Growth Model provide high accuracy and precision compared to the traditional EVM metho

Evaluasi Kinerja Aset Tempat Pengolahan Sampah Terpadu (TPST) di Kabupaten Sidoarjo

Perkembangan Kabupaten Sidoarjo sebagai pusat pertumbuhan membawa dampak terhadap peningkatan jumlah penduduk sehingga berpengaruh terhadap jumlah timbulan sampah yang dihasilkan. Salah satu upaya yang dilakukan pemerintah Kabupaten Sidoarjo untuk mengurangi jumlah timbulan sampah yang masuk ke TPA adalah dengan membangun infrastruktur pengelolaan sampah berupa Tempat Pengolahan Sampah Terpadu (TPST). TPST yang telah dibangun ini perlu menerapkan manajemen aset yang tepat sehingga dapat berjalan secara efektif dan berkelanjutan. Saat ini, masih terdapat TPST yang belum berfungsi optimal salah satunya dikarenakan belum terpenuhi sarana dan prasarana. Tujuan dalam penelitian ini adalah untuk melakukan evaluasi terhadap kinerja aset TPST di Kabupaten Sidoarjo. Metode penelitian yang digunakan adalah analisa deskriptif yaitu menggambarkan suatu data yang terkait pengelolaan aset TPST di Kabupaten Sidoarjo. Pengumpulan data berupa data primer dan data sekunder. Data primer diperoleh melalui observasi lapangan secara langsung dan hasil wawancara, sedangkan data sekunder diperoleh dari hasil studi literatur dan data – data dari instansi terkait. Hasil analisa tersebut memberikan gambaran bahwa kondisi TPST di Kabupaten Sidoarjo masih perlu peningkatan kinerja aset dan pengadaan aset baru. Selain itu juga, perlunya peningkatan kegiatan operasional dan pemeliharaan pengelolaan persampahan agar program TPST berjalan dengan optimal dan dalam rangka berkelanjutan TPST kedepan