Here is how batch-and-queue looks like …on the local road…with stop lights…
Here is how One-Piece-Flow looks like… on a major highway … no stop lights…
Which one can deliver you to your destination faster?
One-Piece-Flow! No stop lights (i.e., no phase gates).
Batch-and-Queue is not cool. Queueing things up in batches for a scheduled SIT ( System Integration Testing) is a common example. A phase gate.
Throw in a complication called ‘Manual SIT Testing’ … and it is a recipe for delayed value delivery… this is a very antiquated practice… not a practice of a modern ‘Factory’
Remediate this antiquated practice to accelerate flow! Automate testing (i.e., Test First, use BDD/ TDD and use cucumber — a test automation tool). Remove Phase Gates by embracing automated CI/CD! Modernize your ‘Factory’!
Obviously, if you cannot modernize your factory, then you will not be able to reduce your Lead Time to deliver value in a quantum leap scale.