Yes, I agree with the statement that Short Run Production Functions are fixed proportion production functions. The short run is a time period where at least one factor of production is in fixed supply. A business has Ghosen it’s scale of production and must stick with this in the short run. We assume that the quantity of plant and machinery is fixed and that production can be altered by changing variable inputs such as labour, raw materials and energy. The time periods used differ from one industry to another
for example, the short run in the electricity generation industry differs from local sandwich bars. If you are starting out in business with a new venture selling sandwiches and coffees to office workers, how long is your long run It could be as short as a few days – enough time to lease a new van and a sandwich making machine