What are the most common causes of Supply Chain disruptions?

Common causes include supplier delays, demand volatility, transport issues, production constraints, data quality problems, and single-sourcing. Often, disruptions are triggered by a combination of factors, such as variable demand plus rigid planning parameters or unreliable lead times. Root causes rarely sit in one place. A late supplier becomes a shortage only when safety stock is undersized, which itself reflects a forecast that did not account for current variability. Treating each cause in isolation tends to produce point fixes that do not last, while addressing the underlying planning logic, with probabilistic forecasts and dynamic buffers, reduces the impact of all of them at once.