This is sooo funny! Makes me laugh all the time I see this visual!
Not only did lean-agile turn the waterfall (predictive) ways on its head, they also turned the famous iron triangle upside down!
This is a powerful image … keep this in your back pocket / mind just in case you get into discussion — about MVP vis-a-vis Cost and Schedule — with a classic waterfall project manager!
In lean-agile, the capacity (capacity cost) is fixed and the schedule (deployment ) will happen (it is on cadence)… it is just a matter of finding that MVP (minimum viable product) or MMF (minimum marketable feature) that fits within those two aforementioned constraints (capacity and deployment schedule/hard milestone). This is the reason why, during PI Planning, hard milestones are posted or surfaced on the Team Plan and Program Board! Team capacity and load are also surfaced during PI Planning! Capacity and deployment (schedule) are both geared towards the delivery of the most prioritized value– the MVP or MMF — highest value with the shortest sustainable lead time for delivery that can fit within those two aforementioned constraints. This is truly a value-driven / vision-driven triangle! The MVP or MMF becomes the vision; features make up the vision; stories — making up the feature– deliver the value. Story must be independent; negotiable; valuable; estimable; small; testable. Features are prioritized and correctly sequenced … and laid out on a Roadmap which consists of a PI or several PIs. This way — roadmap and rightly sequenced features — critical path is evident. This works well in Adaptive environment (i.e. technology industry and other industries — like banking and fintech — that value innovation; value the ability to respond to volatile market conditions, changing customer needs, digital disruptions and emerging technologies).
Contrast that against the waterfall triangle: a plan-driven triangle … estimating the cost of the project and the schedule … with the requirement as the constraint. Work Breakdown structure (WBS) is then laid out vis-a-vis the Schedule. Task are laid out. Critical path seen on the PERT/CPM diagram or on the Gantt Chart. This works well in Predictive environment (i.e. Construction industry).
Lean-agile is geared towards value delivery in small increments. SAFe Principle #4 states: ‘Build incrementally with fast, integrated learning cycles‘. With this in mind, you have a high chance of delivering highly prioritized value — albeit part of small batches — that is immediately usable and of value to the user, with fixed capacity over a set cadence.