Complex sentence: An ongoing inventory method is a system that inventories high value items or items that or more susceptible to theft on a regular basis is a method that resembles an iceberg, with the high value items being at the top of the iceberg.
Split into simpler sentences: An ongoing inventory method is a system that inventories on a regular basis high value items or items that are more susceptible to theft. This method resembles an iceberg, with the high value items being at the top of the iceberg.