Slack is the exact amount/number of resources you have as stock you have in the system
What you should know about a slack is that it is a bad thing; they are just resources waiting in your system unused and cost you inventory costs, certain storage conditions and periodic quality tests. Slack is just "stuff waiting :/ "
What you need is just the right amount of slack in the system
- Just enough to be efficient and not slowing down the flow because of their scarcity
- And not too much be a burden in the system consuming money, time, energy