Ashes 2013: Andy Flower wants to see improvements in use of DRS following latest controversy England coach Andy Flower has called for some "calm decision-making" to try to improve the process of third-umpire referrals in the remainder of this summer's Ashes. Each of the three Tests so far has been beset by a series of controversies over the use of the decision review system - almost exclusively relating to the impact of bat on ball, or otherwise, for caught-behind and lbw appeals. The available technology has regularly contradicted itself, leaving the third official with an awkward judgment call which has inevitably led to contentious outcomes. The concept of 'umpire's call' for lbws - a margin of error within which the initial on-field decision cannot be overturned - is also coming under scrutiny from the critics of DRS. England captain Alastair Cook admitted last night, after the hosts had retained the Ashes in a rain-affected draw at Emirates Old Trafford, that his and Australia's players were "confused" by some of the decisions. Flower has gone a little further today, making it clear he thinks improvements are necessary. "Firstly, umpiring is a very tricky business," he said. But I would say there are very clear protocols to use and to stick to, and I think some calm decision-making needs to be made over the next two Tests. England head to Chester-le-Street, where the fourth Investec Test is due to begin on Friday, with the final match set for The Oval towards the end of this month. "I think there are improvements that can be made," added Flower. There are improvements in the use of the technology and the use of experts who know how to use the technology that could make a difference to getting better results. Cook is also hoping the International Cricket Council can address the situation. He said: "I don't know whether it's because it's the Ashes that the cricketing gods have thrown up so much inconclusive evidence, but we're a little bit confused at the moment as to why certain decisions have been overturned and certain decisions haven't been overturned. Both sides have been quite (confused) by some of the decisions that have occurred. I think it's pretty even, but I hope the ICC can iron things out.