It’s a new year, but the problems for supply chains are much the same. Among them, increasingly, is industrial action.

December drew comparisons with the Winter of Discontent with strikes or threats by Post Office staff, train and tube drivers, airport workers, and even Argos delivery drivers. With the tube strikes this week, that discontent has followed us into 2017.

As others have noted, comparisons with the 1970s are overplayed. It actually became harder for unions to take legal strike action in the UK last year, for example, with the passing of the Trade Union Act in May. Unions now require a ballot turnout of at least 50% for industrial action – and 40% support of all eligible to vote when it comes to vital public services such as health, education, transport, border security and the fire brigade.

Nevertheless, recent activity does suggest something of a resurgence in the UK following a near-record low in the number of days lost to industrial action in 2015. The action we’ve seen also has significant impacts. Academics estimate the Southern Rail strikes alone have cost the UK £300 million. The tube strikes this week may even cost the same, according to some of the higher estimates.

Moreover, while levels of UK industrial action have trended downward in the last few decades and remain modest, they’re much higher elsewhere, including in some of our near neighbours. France, Denmark, Norway, Belgium (which saw a particularly high number of strikes last year), Spain, Finland and Ireland have all lost anything from double to seven times the number of days as the UK to action in recent years. If businesses are not directly affected themselves, others in their supply chain may well be.

All of which is simply a reminder that industrial action remains a key threat to the supply chain. Businesses need to build in resilience and redundancy to account for it, and to do that, they need to have an accurate view of their exposures.