Simulating manpower resources using Monte Carlo simulation

One of PLE's manufacturing plants supplies various engine components to manufacturers of motorcycles on a just-in-time basis. Planned production capacity for one component is 100 units per shift, and the plant operates one shift per day. Because of fluctuations in customers' assembly operations, however, demand fluctuates and is historically between 80 and 130 units per day. To maintain sufficient inventory to meet its just-in-time commitments, PLE's management is considering a policy to run a second shift the next day if inventory falls to 50 or below at the end of a day (after the daily demand is known). For the annual budget planning process, managers need to know how many additional shifts will be needed. The fundamental equation that governs this process each day is:

Ending inventory = beginning inventory + production - demand

Develop a model to simulate 260 working days (1 year), and count the number of additional shifts that are required. Assume that the initial additional inventory is 100 units.

Find the distribution of the number of shifts that the company would expect over the next year. Explain and summarize your findings in a report to the plant manager and make a recommendation as to how many shifts to plan in next year's budget.

I know that demand for the engine components follow a uniform distribution.

How can I write the for loop in R? I think i would need 1 loop to simulate 10000 days and 1 more nested loop to simulate daily demand.

(not sure if this is considered a business question or a statistics question..)