The current bar benders' strike in Hong Kong has brought many construction sites to a halt, and has affected the whole of society. I think this is a resource scheduling problem, and I believe there is a win-win solution.
As skilled labourers, bar benders cut, bend and fix steel beams according to drawings and bending schedules.
Construction technology requires that their work be done after the formwork is completed but before the concrete starts being poured.
It is common practice for a bar bending subcontractor to take multiple jobs at different sites over the same period.
Scheduling such work, over a number of sites and projects, is a complex task.
Let's say a subcontractor has three building sites, and each site has a number of building cycles, or floors, each with its own sequence of tasks. Imagine that he has hired three bar-bending labourers on a relatively permanent basis.
It is quite a challenge to schedule the labourers and the jobs for these sites. If the subcontractor tried to do the jobs in order - first at site one, then two and finally three - the work could take as long as, for example, 111 work days.