>>1141People have a strange obsession with full one way or another economy, which is idealistic.
Socialism, as a realistic system, will basically be a partially controlled capitalism in the luxury sector, and a planned system on the absolutely necessary parts of the economy: agriculture, infrastructure, education, etc. This will last until scarcity is overcome.
Full economic planning is suicide for quite a bit of the point of socialism, which is to take the best of capital's massive capacity for production and desire fulfillment and minimize or erase the negatives of market anarchy (boom and bust, job insecurity, etc.) and eliminate the concentration of capital.
One thing that can theoretically be done is getting rid of private banking. The government banks would function not as lending institutions, but as institutions that realize value, which is the whole point of money- to represent your created value to others. So someone comes in with an idea for a business venture, the bank assesses its feasibility and possible social desirability. You're funded for a first round of production and release your product on the market. If you succeed, your enterprise gets the profit and maintains itself from then on collectively, but privately. If you fail, you're not left in debt, your business dies since clearly your goods are not wanted or needed. instead of closing your business and saying tough luck, the government would have tabs on what people are demanding more and would offer your business restructuring into a new business to meet a known demand. You'd basically have a secure income as you'll never be at a loss for a job. When the point comes that there is no expanding market to shift you into, post monetary measures would have to eventually be brought in and late stage communism begins to take shape.
None of this could even be tried in a single country of course, socialism, like capitalism, will only work on a global scale.