In lean operations terminology a "batch" happens when you're not producing something one at a time. It's when you make multiples of something identical all at once. Usually batching is done to be more "efficient," efficiency being defined as the lowest production cost per unit.
Like binge drinking (another form of batching), batches have strange side effects. One is that when things go wrong they go really wrong. Any error is multiplied by the size of the batch. The bigger the batch, the bigger the error.
You can spot batches everywhere. For example, electricity is often created in large batches. Whether it's made from coal, natural gas, or hydroelectricity, almost all electricity is made in the biggest batch possible. And nuclear power plants are the biggest batchers of them all. It's not one home making electricity for itself. It's one plant making electricity for multiple cities. A typical nuclear plant produces enough power for nearly a million homes.
The nuclear crisis unfolding in Japan made me think about batches and how, when you batch radioactive power generation, you can create some horrific errors, multiplied.