Determine the economic appropriate service life (ESL) of the machine. This requires an initial investment of $10,000, a lifespan of up to 5 years, and in year 1 there are no maintenance costs. As it is still under warranty, maintenance costs will be $600 in year 2 and will increase by $600 per year in subsequent years, with the machine's market value reduced by 20% per annum at an interest rate of 15% per annum. Determine the economic appropriate service life (ESL) of the machine. This requires an initial investment of $10,000, a lifespan of up to 5 years, and in year 1 there are no maintenance costs. As it is still under warranty, maintenance costs will be $600 in year 2 and will increase by $600 per year in subsequent years, with the machine's market value reduced by 20% per annum at an interest rate of 15% per annum. Determine the economic appropriate service life (ESL) of the machine. This requires an initial investment of $10,000, a lifespan of up to 5 years, and in year 1 there are no maintenance costs. As it is still under warranty, maintenance costs will be $600 in year 2 and will increase by $600 per year in subsequent years, with the machine's market value reduced by 20% per annum at an interest rate of 15% per annum.