Time-Cost Trade-Off Model for Tie Beam Activity

Abstract

Crashing project duration is conducted when the project experience schedule delay. The consequence of this crashing is needed the additional cost to anticipate the delay. Choosing the right activity for the reduction will provide additional cost efficiency. The purpose of this research is to develop time-cost trade-off (TCTO) model for tie beam activity. The model was developed based on the respondent's perception through the questionnaire, and collecting the Budget Plan Report. Respondents in this study are director, estimator, and project manager at contractor who is domiciled in West Aceh District. The results showed that the tie beam can be broken down into sub activities such formwork, rebar and concrete that have different characteristics in tie beam activities based on TCTO model. Based on these conditions, the sub activities activities can be accelerated from the normal duration of the project are 60%, 50% and 60% respectively and the required additional cost is 2.88% per day, 2.93% per day, and 3.88% per day.Keywords : Project Crashing, Crash Duration, Additional cost, Model TCTO, Tie beam, West of Aceh, Formwork, Rebar work, Concrete workAbstrak: Percepatan schedule sering dilakukan ketika kemajuan proyek dinilai mengalami keterlambatan terhadap rencana awal. Konsekuensi dari percepatan schedule tersebut dapat memberikan peningkatan biaya proyek. Pemilihan aktifitas yang tepat akan memberikan efisiensi biaya tambahan. Penelitian mengkaji hanya pada aktifitas sloof sebagai aktifitas yang dipilih untuk di percepat sebagai obyek tinjauan. Tujuan dari penelitian ini adalah mengembangkan model Time-cost trade-off (TCTO) aktifitas pekerjaan sloof dalam sebuah proyek. Model tersebut dikembangkan berdasarkan persepsi responden melalui pengisian kuesioner dan data RAB. Responden dalam penelitian ini yaitu direktur, estimator, dan manajer proyek pada badan usaha kontraktor yang berdomisili di Kabupaten Aceh Barat. Hasil penelitian menunjukkan bahwa pekerjaan sloof dapat dipecah kedalam sub aktifitas seperti sub aktifitas bekisting sloof, pembesian sloof dan beton sloof memiliki karakteristik yang berbeda dalam pekerjaan sloof berdasarkan TCTO model. Berdasarkan kondisi ini, sub-aktifitas pekerjaan sloof tersebut dapat dipecepat dari durasi normal proyek secara berturut-turut adalah 60%, 50% dan 60% dan biaya tambahan yang diperlukan adalah 2.88% per hari, 2.93% per hari, dan 3.88% per hari.Kata kunci : Percepatan schedule, Durasi crash, Biaya tambahan , Model TCTO, Pekerjaan sloof, Aceh Barat, Pekerjaan bekisting, Pekerjaan pembesian, Pekerjaan pengecoran

Sub-activity Time-Cost Trade-off Model of Building Structural Beam on the Projects in the North Aceh Region

“…The findings of the TCTO model of each sub-activity are linearly indicated of constant increment of the additional cost. It is a logical and natural thing, where this model practically represents the same daily pattern acceleration, as in line with (Deckro and Hebert, 1990;Zeinalzadeh, 2011;Fachrurrazi et al, 2018b). It is the inductive research conducted in North Aceh District as puzzled research for applied to a wider area such as Aceh.…”

“…The normal cost standard is analyzed using Eq. (2) as in (Fachrurrazi et al, 2018b). Crash Duration ( 6 ) is the maximum of the possible compressed duration for each activity based on respondent judgment.…”

“…The deviation of normal duration ( 5 ) and crash duration ( 6 ) is defined as the reduced duration of activity (∆ ), as calculated by Eq. (3) of (Fachrurrazi et al, 2018b). Crash cost is a cost incurred when the crash duration is reached.…”

“…Based on the based on a formula that has been derived, we analyze the crash cost ( 6 ) using Eq. (7) as in (Fachrurrazi et al, 2018b):…”

“…Elbeltagi (2009) states that the compressed duration of the project can cause a slope change from the time-cost curve when conducting the acceleration of project activities, which is analyzed using eq.(8). (Fachrurrazi et al, 2018b) Aceh Int. J.…”