operational and planning variances

hello, i have a litte problem with this thing, when we calculate price planning variances should we use the revised quantity or the actual quantity and how about usage operational variances should use standard price or revised standard price? I get confused on this when i try to answer past year question, no.1(b) december 2009 on Secure Net(SN). Secure Net (SN) manufacture security cards that restrict access to government owned buildings around the world. The standard cost for the plastic that goes into making a card is $4 per kg and each card uses 40g of plastic after an allowance for waste. In November 100,000 cards were produced and sold by SN and this was well above the budgeted sales of 60,000 cards. The actual cost of the plastic was $5·25 per kg and the production manager (who is responsible for all buying and production issues) was asked to explain the increase. He said ‘World oil price increases pushed up plastic prices by 20% compared to our budget and I also decided to use a different supplier who promised better quality and increased reliability for a slightly higher price. I know we have overspent but not all the increase in plastic prices is my fault’ The actual usage of plastic per card was 35g per card and again the production manager had an explanation. He said ‘The world-wide standard size for security cards increased by 5% due to a change in the card reader technology, however, our new supplier provided much better quality of plastic and this helped to cut down on the waste.’ SN operates a just in time (JIT) system and hence carries very little inventory. (b) Analyse the above total variances into component parts for planning and operational variances in as much detail as the information allows.