No abstract

AbstrakBaja yang digunakan sebagai bahan baku pada proses manufaktur dan konstruksi dituntut memiliki kualitas yang baik. Pada proses produksi, untuk menghasilkan baja dengan kualitas baik masih terdapat beberapa masalah yang timbul, salah satu penyebabnya adalah penurunan kualitas air. Tujuan dari penelitian ini adalah menganalisa faktor yang mempengaruhi kualitas air dalam produksi plat baja, serta strategi pengendaliannya. Metode yang digunakan adalah six sigma dan seven tools. Beberapa faktor yang mempengaruhi faktor kualitas air seperti adalah pH, Cl, Turbidity, SS, Fe, m-Al, Ca-H, PO4. Hasil analisa data menunjukkan bahwa turbidity dapat menyebabkan terbawanya partikel kerak besi dari air sehingga akan menyebabkan cacat pada permukaan plat. Faktor kualitas lainnya seperti pH juga berdampak pada tingkat korosifitas mesin dan perpipaan berbahan besi, semakin asam atau basa suatu larutan maka tingkat korosifitas semakin kuat. Berdasarkan pengujian sampel air diperoleh data parameter turbidity mengalami penyimpangan paling besar dibandingkan dengan parameter lain sehingga penanganan pada parameter ini harus diprioritaskan. Semakin besar nilai turbidity maka semakin besar potensi terbawa partikel kerak besi yang mengakibatkan terjadinya penumpukan dan penyumbatan pada pipa. Berdasarkan analisis pengendalian kualitas menggunakan six sigma diperoleh nilai RPN suplai air yang kotor sebesar 579, nilai RPN turbidity sebesar 512, nilai RPN pH sebesar 448, nilai RPN Fe sebesar 392 dan nilai RPN Alat penyaringan/filter air tidak menyaring secara optimal sebesar 336. Kata kunci: kualitas air, baja, six sigma, seven tools. AbstractNowadays, steel needs in the industrial and housing sectors are the most fundamental needs. Steel is used as raw material in manufacturing and construction processes so that good quality steel is required. In the production process to produce good quality steel there are still some problems that arise one cause of the quality of steel due to water quality degradation. Six sigma method is used for water quality control and seven tools method is used to analyze the factors causing water quality decrease. Several factors affect water quality factors such as pH, Cl, Turbidity, SS, Fe, PO4. After the data is analyzed it is known that turbidity can cause the carrying of iron particles from the water so that will cause defects on the surface of the plate. Other quality factors such as pH have an impact on the level of engine corrosivity and steel piping. The more acidic or alkaline a solution the higher the corrosive level. Based on testing of water samples obtained turbidity parameter data experienced the largest deviation compared with other parameters so that handling on this parameter should be prioritized. The greater the value of turbidity, the greater the potential carrying iron crust particles that resulted in the buildup and blockage of the pipe. Based on analysis of quality control using six sigma obtained RPN value of dirty water supply equal to 579, RPN turbidity value 512, RPN pH value eq...

Construction of the Provincial road project from Parigi to Sukamanah is carried out by PT. Jaya Madiri Konsulindo as consultant and PT. Karya Tunas Mandiri Persada as contractor. The problem of the construction project is implementation duration does not match to previous planning which results delay in completion time. It is necessary to re-plan the project in order to get either optimal time or cost. The purpose of this research is to find out the critical work path using critical chain project managemet method by utilizing microsoft project software and optimization of project time and cost using crashing method with alterative increase of working hours (overtime) and addition of labor. The research' scope is limited on labor cost only. Based on the results of the study obtained that initial labor wage cost is IDR 585,025,000.00 with a working duration of 154 days, and results of the alterative crashing method is lower with labor wage cost IDR 576,750,000.00. It could save cost about IDR 8,275,000.00 with duration of work 150 days or earlier 4 days from the initial duration.