Answer :
A business cycle (or economic cycle) measures the downward and upward of the country's GDP (Gross Domestic Product) within an economic boom and recession, in sequence. It's a long-term measure and it usually presents high fluctuations of the GDP between its extremes.
Since the GDP represents the productive capacity of a country, it is directly related to the supply and demand of its products.
So from this perspective, a boom in the economy represents a higher purchase power by customers, and hence a higher need for production. This prompts the hiring of more workers to increase the production and supply this demand.
In the hard goods sector, this overproduction is usually followed by an economic contraction, due to high stocking after the customers' needs are attended. This contraction, if too severe, forces the companies to drastically reduce production, and sometimes promote a mass resignation, which is a common cause for a huge recession.
Note that this overproduction factor is not an exclusive determinant for a recession. Other factors may cause one! To which, the same consequences would apply.