Having spent the best part of 15 years looking at public procurement data, this is my take on collapse of Carillion. It has caused chaos for a simple reason: the organisation's tentacles reached into all parts of government, with more than 200 public bodies signing some form of contract with Carillion in the last five years. The sums spent by the government on Carillion were huge: in 2016, this amounted to nearly £1bn. As a result, it goes without saying that many government departments have been badly affected by the firm's demise this week. The worst hit is likely to be Carillion's biggest customer: the Ministry of Defence. In the last five years, the MoD has forked out over £2.2bn – and this is just the stuff we know about.