“Estimation of the Optimum Period for the Replacement of Machines Using the Age Replacement Model Under the Minimum Cost Criterion”. 2022. Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ) 52 (2): 1-10. https://doi.org/10.55562/jrucs.v52i1.537.