The explosion method with B/M has two aspects: one is explosion form, and the other is explosion direction. The explosion form is divided into three depending on the type of the level of structure B/M: Single Level Explosion, Indented Explosion, and Summarized Explosion. In the Single Level Explosion, one upper-level (parent) items or one lower-level (child) items of the item are explored, in the Indented Explosion, multi-level upper items or multi-level lower items of the item are explored, and in the Summarized Explosion, all the upper-level or lower-level items are explored in the ascending order of level. On the other hands, explosion direction is divided into two: Explosion where the lower items (child, grandchild, or lower-level) are searched and Implosion where the upper items (parent or upper-level) are searched. Explosion shows what items the item consists of, while Implosion shows what items the item is used for. By combining these explosion forms and directions, there are the following six types of explosion methods. See "Parts Explosion".

Related term: Bill of Materials