The goal of the Five Year Plans were to modernise Soviet industry. Stalin claimed that the USSR was 50 to 100 years behind the west, and that if they could not make up this gap within 10 years or the West would bury them - he was very nearly right.
The Five year plans were Stalin's method of modernising the country's industry. New dams, for hydro-electricity, new roads, new steel & metal plants were created, new mines sunk and new canals dug.
Economically they were a success, enabling the Soviet Union to not feel the effects of the Great Depression - in fact to benefit from it, as they needed machinery & the expert operators to train their workers - and the West was keen to sell them the machines and operators were available to go to the USSR to work them.
Politically the Five Year plans were a success, they consolidated Stalin's position as supreme leader, and they were ideologically more Marxist than the previous policy - the New Economic Policy, which pleased many in the party.
Socially the results are mixed. Initially there was great enthusiasm for them, and many people volunteered to work on the grand projects, the country was electrified and many new jobs were created. But political prisoners were used as workers on many of them - notably the Belomor canal - and many people died as a result. And the continued use of Five Year Plans proved to be catastrophic, the Global economy changed rapidly after WWII, by the Soviet Union's didn't - it was still producing plans based on the realities of the 1930s in the 1980s. Consumer goods were not a priority, heavy industry was always favoured, and food supply networks were not expanded or developed, causing shortages and queues in the 1980s, undermining people's faith in the system.
But their greatest success was that they built the infrastructure that was able to take the Nazi hammer blows, and the FYPS put in place the system to eventually beat them.
Stalin, A Biography - Robert Service
Stalinism & After - Alec Nove
Stalin's Industrial Revolution - Hiroaki Kuromiya