The call to bare arms is now widespread. In Argentina. In Germany. In Indonesia. In fact, we see the call to arms in all the countries that have secured supplies of the vaccine to fight the Covid-19 pandemic. It is a call for upper arms to be bared, and injected.

Our time to bare arms will come when SA has procured supplies. Securing supply is where the (acrimonious) discourse is currently focused. Let’s use the time until steady supply is available to get ready to bare arms across the nation. Is it a time for National Service for all continuous improvement practitioners (Lean or Six Sigma or TQM or Industrial Engineer; whatever they call themselves)?

South Africa has a population of 60 million. To achieve herd immunity, we need 60-70% of us to be vaccinated; let’s call it 66.7% or 40 million. What is the takt time (T) if we aim to achieve herd immunity in 6 months, working an effective 12 hours a day, 7 days a week? It turns out to be 0.0967 seconds per jab, each person needing two jabs; that’s about 620 jabs per minute. Pretty quick, hey? But it assumes only one delivery point, i.e., just one point at which 40 million people bare arms.

So, how many delivery points do we need? Well, if the time to give an injection is ‘t’ seconds, and we have ‘n’ delivery points, we find this relationship: t/n = T. For practical reasons, T is the maximum time, so in fact we must look for t/n <= T, so that n >= t/T.

The UK’s Daily Mail Online reports that at one mass vaccination centre, with six queues, they hope in time to achieve 4 jabs per minute. That means their target ‘t’ is 90 seconds. Maybe they start at 180 seconds and use continuous improvement to get down to 90 seconds per delivery point? So, maybe the average over the period is 135 seconds?

Using t = 135 seconds, SA will need at least 135/.0972 delivery points; works out as 1388. But this is not realistic. A buffer time per injection is needed; let’s say we allow a 20% buffer. Then we need at least 1667 delivery points, each working an effective 12 hours each day (say 2×8-hour shifts), 7 days a week, for six months.

Well, that’s the big picture. Takt time is a valuable guide to the cadence or rhythm at which a system needs to work to meet customer demand in a specific period. The equation has nothing to do with resources, only time and customer demand. It speaks to the speed at the bottleneck process in a long logistical chain: from suppliers to the vaccine manufacturer, from vaccine manufacturer to bulk store, to regional store, to mass vaccination centre, to delivery point. Another supply chain has to converge at that point: people must be available and baring arms at each delivery point every 135 to 162 seconds.

Each of those 1667 delivery points will need to be set up, staff identified and trained, transport arranged for the public, stabilized, improved, etc., etc. It is the time for operations management skills. If we are to achieve herd immunity in a reasonable time, 40 million people need to bare arms. Time to call up the lean troops to National Service?

Norman Faull
Chairperson, Lean Institute Africa