The lead time indicates how long it takes for a work item to go through the entire process. Cycle time is a subset of lead time. Cycle time is the time it takes for a work item to go through part of the process (e.g., In Progress to Done status, from the coding phase to the testing phase, Complete a task).
There are several strategies for lead time and cycle time problems, such as increasing system’s efficiency, increasing capacity (crashing), and stop taking requirements (not always possible).