Suppose that in the inventory problem, there is an annual cost, [tex]$k_1$[/tex], for storing a single unit, plus an annual cost per unit, [tex]$k_2$[/tex], that must be paid for each unit up to the maximum number of units stored. The number of units that should be ordered or manufactured to minimize the total cost in this case is

[tex]$q=\sqrt{\frac{2 m}{ k _1+2 k _2}}$[/tex].

Every year, Gianna sells 144,000 cases of her Famous Spaghetti Sauce. It costs her [tex][tex]$\$[/tex] 2$[/tex] per year in electricity to store a case, plus she must pay annual warehouse fees of [tex]$\[tex]$ 2$[/tex][/tex] per case for the maximum number of cases she will store. If it costs her [tex]$\$ 750$[/tex] to set up a production run, plus [tex]$\[tex]$ 9$[/tex][/tex] per case to manufacture a single case, how many production runs should she have each year to minimize her total cost?

Gianna should have [tex]$\square$[/tex] production runs each year to minimize her total costs.



Answer :

To determine the optimal number of production runs Gianna should have each year to minimize her total costs, we need to use the provided formula and the given data.

The relevant formula for determining the optimal order quantity [tex]\( q \)[/tex] in the inventory-problem is given by:
[tex]\[ q = \sqrt{\frac{2 \times \text{annual demand} \times \text{setup cost}}{k_1 + 2 \times k_2}} \][/tex]

Where:
- Annual demand ([tex]\( m \)[/tex]) = 144,000 cases
- Cost per year in electricity to store a case ([tex]\( k_1 \)[/tex]) = \[tex]$2 - Annual warehouse fees per case (\( k_2 \)) = \$[/tex]2
- Setup cost ([tex]\( \text{setup cost} \)[/tex]) = \$750

First, we need to compute the total storage cost per unit:
[tex]\[ \text{total storage cost per unit} = k_1 + 2 \times k_2 \][/tex]
[tex]\[ \text{total storage cost per unit} = 2 + 2 \times 2 \][/tex]
[tex]\[ \text{total storage cost per unit} = 2 + 4 \][/tex]
[tex]\[ \text{total storage cost per unit} = 6 \][/tex]

Now, substitute the values into the formula for [tex]\( q \)[/tex]:
[tex]\[ q = \sqrt{\frac{2 \times 144,000 \times 750}{6}} \][/tex]
[tex]\[ q = \sqrt{\frac{216,000,000}{6}} \][/tex]
[tex]\[ q = \sqrt{36,000,000} \][/tex]
[tex]\[ q = 6,000 \][/tex]

So, the optimal order quantity [tex]\( q \)[/tex] is 6,000 cases.

Next, to find the number of production runs needed each year, we use the formula:
[tex]\[ \text{production runs per year} = \frac{\text{annual demand}}{q} \][/tex]
[tex]\[ \text{production runs per year} = \frac{144,000}{6,000} \][/tex]
[tex]\[ \text{production runs per year} = 24 \][/tex]

Therefore, to minimize her total costs, Gianna should have 24 production runs each year.