ROT and AROT Method Week #5
Runout Time (ROT) Sebuah metode untuk menentukan urutan produksi untuk grup-item yang diproduksi pada alat yang sama.
Runout Time (ROT) Method Item Standard Hours per Unit Production Lot Size (units) Demand forecast per period (unit/week) Current inventory position (units) Standard Hours per Lot Size (col. 2)(col. 3) A 0.1 100 35 10 B 0.2 150 50 120 30 C 0.3 40 130 D 200 60 Total 110 Lakukan scheduling untuk urutan produksi dari ke-4 item produk diatas dengan menggunakan aturan ROT. Jika kapasitas produksi yang tersedia 90 jam per minggu, apakah kapasitas produksi ini cukup?
Current Inventory Position (units) Demand per period (units/week) Item Current Inventory Position (units) Demand per period (units/week) ROT (weeks) (col. 2)/(col.3) Sequence A 100 35 2.86 3 B 120 50 2.40 2 C 130 40 3.25 4 D 60 1.67 1 Sequence ROT (weeks) Lot Size (units) Machine hours per lot size Remaining capaity (hours) D 1.67 200 40 50 B 2.40 150 30 20 A 2.86 100 10 C 3.25 -20
Aggregate runout time (AROT) Metode penjadwalan yang digunakan untuk grup-item untuk menghindari kekurangan (shortage)
Item Standard Hours per Unit Demand forecast per period (unit/week) Machine hours for demand forecast (col.2)(col.3) Corrent inventory position (units) Inventory machine hours (col.2)(col.5) A 0.1 35 3.5 100 10 B 0.2 50 120 24 C 0.3 40 12 130 39 D 60 20 Total 37.5 93 AROT = (total inventory in machine hours + total machine hours available) / total machine hours forecasted per period = (93 + 90)/37.5 = 4.88 weeks
Demand forecast per period (unit/week) AROT (weeks) Item Demand forecast per period (unit/week) AROT (weeks) Gross Requirements (units) (col.2)(col.3) Current inventory position (units) Lot size (units) (col.4) – (col.5) A 35 4.88 171 100 71 B 50 244 120 124 C 40 195 130 65 D 60 293 193 Total Item Standard Hours per Unit Lot size (units) Machine hours required (col.2)(col.3) Remaining capaity (hours) A 0.1 71 7.1 82.9 B 0.2 124 24.8 58.1 C 0.3 65 19.5 38.6 D 193 Total