No Test Plan or Strategy

There is no Test Plan and/or Strategy, or it's not efficient (e.g. not focused on end user's flow or critical path).

Discovered by combination of metrics:

Velocity: Committed vs. Completed, when testing takes too much time in the delivery pipeline resulting in product increment not meeting definition of done by the end of iteration

Time in Status, when testing is suspiciously quick

Defect Containment, if internal team skips significant amount of valid issues which are captured by the external team during product acceptance or upon release / in production 

Invalid Defects, when it keeps on a high level as there is no process of issue analysis against acceptance criteria and expected result of the system behaviour 

Recommendations: 

1. Introduce or enhance Test Approach

2. Enhance Sprint execution

3. Keep iron triangle in balance