In a phased-and-gated process, each phase is a batch of activities that must be completed to produce a set of deliverables. These deliverables are reviewed in a batch at a gate. This method’s problem is that the batch is held until the batch’s longest activity is completed (1). The bigger the batch, the more likely it is that work will be held up, waiting for the batch to complete.
In contrast, ExPD emphasizes adaptability and flexibility, not large batches. The team gains speed by breaking up project uncertainties into smaller batches / short sprints. Several benefits include:
• Faster feedback. Quick experimentation and iteration allow the team to quickly identify and resolve the most significant risks and uncertainties.
• Faster cycle times. Typically, each item in a batch cannot advance to the next step until the batch’s longest activity is completed. In smaller batches, fewer activities are on hold, waiting for approval to move on.
• Shorter queues. We know from queueing theory that smaller batches result in shorter queues of tasks waiting for a team member’s attention, resulting in less idle time (2).
This is an excerpt from our soon-to-be-released book, “ExPD: Adaptable Product Development for a Changing World.”
(1)Donald G. Reinertsen, The Principles of Product Development Flow (Redondo Beach, CA: Celeritas, 2009).