5.2. Determining Economic Life

So, equipment life: So, basically there are different phases in the equipment life as everyone knows. So, it starts with the purchase of the machine. We purchase the machine first, then we start using it. As we use it, with age, the machine ages, you can say that the machine will be subjected to more amount of wear and tear. So, once it is totally worn out, when it comes to the end of the useful life of the machine, we go for the replacement of the machine.

The life of equipment can be divided into different phases. Initially, a machine is purchased, and then it is put to use. Over time, as the machine ages, it experiences wear and tear from usage. Eventually, this wear leads to a point where the machine's performance deteriorates to such an extent that it can no longer operate efficiently. At this stage, it is considered to have reached the end of its useful life, and replacing it becomes necessary to maintain productivity.

Think of a car that you buy for daily commuting. Initially, it runs smoothly, but after several years of driving, the car starts showing signs of wear—like engine problems or brake issues. Eventually, repairing it becomes too costly compared to buying a new car, much like how machinery reaches a point where replacement is the more economical choice.

Generally we replace at a particular point, when the machine is totally worn out. That means it will not be economically feasible for us to repair it and use it. So, at that stage, what we do is we either abandon it or scrap it or sell it at a reasonable price and replace the old machine with a new machine. So, these are the common phases in any equipment life. So, for a profitable equipment management, there are certain decisions which are very important.

When a machine wears out completely, it may no longer be cost-effective to repair it. At this point, owners generally have three options: abandon the machine, scrap it for parts, or sell it to recoup some financial value. The decision to replace involves considering factors like economic feasibility and productivity. The goal of these decisions is to enhance profitability in equipment management.

Imagine you have an old bike that requires constant repairs. If the cost of repairs is approaching the price of a new bike, it makes sense to consider buying a new one. Just like with machinery, the decision hinges on maintaining the economic feasibility of ownership.

So, once this decision is a replacement decision. Whether to replace your old machine with a new machine or not, if at all you decide to replace, then to make the replacement. So, what is the optimum replacement time? So, these two are very important questions or these two are the important decisions which are to be made accurately from profitable equipment management perspective.

The decision to replace equipment is not straightforward—it involves assessing whether it is indeed time to replace the old machine and determining the best time to do so. This 'optimum replacement time' is crucial because replacing too early may waste potential utility, while waiting too long might incur higher repair costs or lost productivity.

Consider a smartphone; you might keep it until it starts lagging severely or can't run the apps you need. However, if you wait too long, the performance may dip so low that it affects your daily life, making it inefficient to use. Finding the right time to upgrade is key.

What is this economic useful life, I will be discussing more in detail in the upcoming slides. Basically, economic useful life is the time period during which the cost associated with the machine is minimum. The total cost, the cumulative total cost associated with the machine is minimum.

Economic useful life represents the time during which it costs the least to own and operate a machine. This encompasses both operational costs and maintenance costs over its useful life, designating a specific time frame when the equipment provides the best value versus its cost.

Think of an investment account that grows over time. There’s a period when your money is earning interest optimally, and pulling it out too soon means you miss out on that growth. Similarly, the economic life of machinery reflects the period when it would be most cost-effective to use it.

To make this replacement decision, so we need some knowledge on how to estimate the economic useful life of the machine. If you know this economical useful life of the machine, at the end of this useful life of the machine, we have to replace our old machine with a new machine, because we never want the profit to get reduced.

Understanding the economic useful life enables decision-makers to plan ahead. By knowing when a machine will start costing more than it saves, they can replace it proactively. Failing to replace machinery at the right time can lead to diminished profits and increased operational costs.

Just as one would plan to replace a refrigerator before it breaks down completely, based on its age and performance, businesses need to track machinery performance to make timely replacements before they start incurring losses.

So, basically economic useful life is a part of profit life. Economic life ends when the profit is maximum, you can see the economic life ends when the profit is maximum. Generally, the equipment owners from the business perspective, we can see that we never want our profit to get eroded.

Economic life is closely tied to profit. This phase ends when profits are maximized, suggesting that if a machine is retained beyond this timeframe, profits may begin to erode because of increased operational costs and repairs. Thus, business must ensure they do not extend the use of machinery past this peak profitability point.

Imagine owning a popular restaurant; your menu might feature dishes that are trending. If you wait too long to innovate and replace less popular items, your sales will decline. Similarly, machines must be replaced before they fall behind in efficiency or profitability.

So, now let me define you what is the equipment life? There are different ways to define the equipment life. This graph shows you the pictorial presentation of the equipment life, you can see. So, you have the replacement age in the X-axis and you have the profit in the Y-axis.

The equipment life can be depicted graphically, where the X-axis often represents the age of the equipment while the Y-axis measures profit. This visual representation helps to understand how profit varies during the life of the equipment and identifies key periods for replacement based on this relationship.

Think of a sports car that performs best in its first few years. If you chart performance over time, it peaks early and then gradually declines, illustrating when to sell or trade-off the car to maximize resale value, similar to machines that need replacement after reaching their prime.

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