Simulasi Penentuan Biaya Pengadaan Material dengan Menggunakan Metode JIT dan POQ

Abstract

Research on simulating the cost of procuring materials using the JIT and POQ methods was conducted at the office of the BUKIT-ARMONACA contractor company KSO Medan, North Sumatra. Armonaca KSO is a contractor company that handles various projects. The construction of these projects always requires the procurement of materials such as cement, sand and gravel. In 2019, there was work on the construction of the SIBISA terminal which required various materials, but due to the poor management of the procurement of materials owned by the company, overstock and stockouts often occurred. For this reason, it is necessary to evaluate the process of procuring goods/raw materials against the total cost of procuring these raw materials. The evaluation is carried out by simulating the implementation of the raw material procurement process using the System Dynamic method with the help of Anylogic Software. In the simulation model, 2 scenarios were carried out, namely the Just in Time (JIT) scenario and the Periodic Order Quantity (POQ) scenario, then the simulation was carried out for 17 weeks (weeks). Model verification is done to see if there is an error in the model. Model validation uses the Mean comparison (E1) and Percentage of Error Variance (E2) and the results show that the E1 and E2 values of the cement acceptance, sand acceptance and gravel acceptance variables are valid, namely E1 ≤ 5% and E2 ≤ 30% it can be concluded that the model is acceptable. From the experimental results it was found that the scenario chosen was the Just In Time (JIT) scenario, this scenario was chosen because the calculation results obtained that the total cost of material procurement for the JIT scenario was Rp. 565,359,606 where the JIT scenario is able to reduce the value of the total material procurement costs before the scenario is carried out by Rp. 4,692,137.