Operational Cost Models for an Earth Station System Using 2-Parallel and 4-Parallel Configurations

Abstract

Operational cost is important in any system. In the case of the earth station system, operational cost is very crucial. The operational cost can be divided into three costs: maintenance, failure, and replacement costs. There are many complex subsystems incorporated in the earth station system, for instance a high-power amplifier, modulators, and antennas, to name a few. In this research, only the replacement cost was considered. Moreover, there are many replacement methods that are available. These replacement methods implicitly influence both the replacement and the replacement costs. The aim of this research is to provide a new cost model based on which replacement method yields the lowest cost. Two replacement methods are involved in this research: failure-triggered and age-based. The failure-triggered and the age-based replacement methods were considered because these methods are the most used in previous research work. Furthermore, three types of cost models were also considered, and they were linear, polynomial, and exponential operational cost models. The outcomes show that the failure-triggered and age-based replacement methods of 2-parallel configuration of polynomial and linear operational cost models yielded the lowest RMSE value of 2.5. Therefore, both polynomial and linear operational cost models of the 2-parallel configuration were the most optimal operational cost models.

ABSTRAK: Kos operasi adalah penting dalam mana-mana sistem. Dalam kes sistem stesen bumi, kos operasi adalah sangat penting. Kos operasi boleh dibahagikan kepada tiga kos: kos penyelenggaraan, kegagalan dan penggantian. Terdapat banyak subsistem kompleks yang digabungkan dalam sistem stesen bumi, contohnya penguat kuasa tinggi, modulator, dan antena. Penyelidikan ini hanya membincangkan tentang kos penggantian. Selain itu, terdapat banyak kaedah penggantian sedia ada. Kaedah penggantian ini secara tersirat mempengaruhi kedua-dua kos penggantian dan penggantian. Matlamat penyelidikan ini adalah bagi menyediakan model kos baharu berdasarkan kaedah penggantian yang menghasilkan kos terendah. Dua kaedah penggantian yang terlibat dalam kajian ini: penggantian yang dicetuskan oleh kegagalan dan berdasarkan umur. Kaedah cetusan kegagalan dan penggantian berasaskan umur telah dipertimbangkan kerana kaedah ini paling banyak digunakan dalam penyelidikan terdahulu. Tambahan, tiga jenis model kos turut dipertimbangkan, iaitu model kos operasi linear, polinomial dan eksponen. Dapatan menunjukkan kaedah penggantian cetusan kegagalan dan berdasarkan umur melalui konfigurasi model 2 selari bagi kos operasi polinomial dan linear menghasilkan nilai RMSE terendah iaitu 2.5. Oleh itu, kedua-dua model kos operasi polinomial dan linear bagi konfigurasi model 2 selari adalah kos operasi paling optimum.