The first FYPs were an ideological response to the previous policy - the New Economic Policy (NEP). NEP allowed small businesses to operate and was creating a middle class. The Communists were never happy with this policy as Marx stated that communism could only happen when the workers owned the means of production. The FYPs, as the state was a "workers state" saw the workers - i.e. the state own all the means of production. This changed the country from having private enterprise (albeit at a small level) as the main economic driving force, to having the state - and its planning arm - Gosplan as the main driving force.
Positives: Transformed the country - much of the country was electrified, huge civil engineering works and massive new factories brought change in the way that people worked. Agriculture was transformed from an inefficient peasant based and labour intensive activity to an inefficient, worker (collective farm workers received wages) based and more mechanised activity. It also solidified the gains of the revolution - the revolutionary elite can, after the first FYP really be called the political class. This means they can start to act like a political elite - not like an underground movement.
Negatives: The kulaks - richer peasants - were deported to Siberia and the Kazakh steppe. This ideological decision rooted out the most efficient, often the most educated and the most entrepreneurial farmers and destroyed them.
The civil engineering works were completed with little regard to quality - the Belomor canal, dug at huge cost in human life (prisoners, both criminal and political were used to dig it) but it was not deep enough for the ocean going ships it was designed for.
Stalin used the political turmoil following Lenin's death and the to isolate, eliminate and to, on occasion, to execute his rivals. The political elite lived lives of fear - fear that a misplaced word or an conceived look could lead to a knock on the door in the middle of the night.
In agriculture the policy was to merge all of the small farms in an area into a collective, know as either a Kolkhoz or a Sovkhoz (depending on who the land was owned by before collectivisation).
Collectivisation was begun for ideological, political and economic reasons;
Ideological - Stalin was a Marxist and, as such, was concerned that the farms being in private ownership would create a class of bourgeois farmers, in fact this was beginning to happen under the New Economic Policy as some peasants began to improve their land and make enough money to employ people to work for them. Collectivisation was put in place to turn peasants into workers. The collective would own the land and the buildings, the Machine Tractor Station would own the large machinery, tractors, harvesters and so on and the farmers would be employees, paid a wage by the farm.
Political - The peasants had a long history of radicalism and terrorism in Russia, the Narodnik movement that turned into the Socialist Revolutionary Party had been responsible for the assassination of Tsar Alexander I and hundreds of of other attacks on lesser figures. In order to clamp down on any potentially counter-revolutionary movements in the countryside collectivisation - each farm had a soviet with a party member - was imposed on the peasants.
Economic - Farming in Russia was primitive and WWI and the Civil War had seen agricultural output drop considerable. NEP and the associated agricultural policies had seen output rise, but by nowhere near the amount needed in order to create a surplus large enough to export in order to fund the first phase of the Five Year Plans. Collectivisation brought mechanisation, rationalisation to the many small plots that peasants worked on and put in place the distribution and supply networks needed to modernise agriculture and to produce enough grain for export.
As to the failures of collectivisation - this is a loaded question as by the criteria given it succeeded in all counts. However, it did fail as a system of agriculture. Output fell in the 1930s - largely for three reasons:
1, the peasants resented the state taking their land, machinery and livestock, so they did not work as hard and put more effort into their private plots, where they could keep any profit generated - who wouldn't? These private plots - some 5% of the land provided as much as 25% of the agricultural produce of the country. Alongside the implementation of collectivisation was the policy of liquidating the kulaks. The Party said these were rich farmers - in reality they were the better farmers, they had improved their land and had a better understanding of their land and what to grow and how to grow it than the others in their village, the eradication of these people was a massive mistake - they should have been put in place as the managers of the collectives.
