Your workload has been established, you are a happy planner. You now need to break that workload down to assignable work or into workable shifts. You need to determine start and end times of shifts and their durations.
There are many ways to establish the shifts and it mostly depends on the industry your business is in. Manufacturing industries for example will start their business with one day shift on a weekly basis. This gives them a certain capacity that can accommodate some business growth. Once that capacity is surpassed, an evening shift will be added later in the life of the business and so on. The business may elect to use 12-hour shifts instead of 8-hour shifts, but in the end, the shift start and end times are pre-determined. Therefore, in these types of businesses, this step can be skipped since there are not really any questions on how to break down the work.
Other businesses like retail will carve their shifts according to the employees’ availability and will determine start and end times based on the employee who would work that shift. Although you may think these types of businesses don’t break down the work by itself, they actually do. Best practice is to compare what you could do if you had the availability you need with the availability you have. So carving the shifts without looking at the employees who would work them gives a good view of a breakdown that would reduce the number of shifts and make the best coverage possible. It is easier to break down a shift or change it afterwards to match an employee but do it knowingly.