Identify bottlenecks and establish the right strategy for optimal production
The Theory of Constraints (ToC) is a management paradigm to ease flow. It is based on the novel “The Goal” [Goldratt 1984] which exposes the idea that "a chain is no stronger than its weakest link". Goldratt proposes 5 steps to implement the ToC:
Simply put, you should remove any bottleneck except if it impedes any other part of the organization in order to support a systemic view. Bottlenecks are not always what and where we think they are and Gemba walks will help you to spot genuine issues [Marris 2016].
At a bird view, there are four kind of organization named VATI [Cox 2010]
At a lower level, the ToC proposes a model named “DBR” [Cox 2010] for Drum-Buffer-Rope:
The DBR teaches the processes should apply cadence based on the slowest process to avoid congestion [Cox 2010]. The cadenced system shown above should then be aligned with the process #2.
The DBR part of the ToC states that the process steps upstream of a bottleneck should be aligned with the slowest part of the process. Therefore, if testing is done at the end the ideation process (development included) should wait for the end of testing with a “rope” to trigger new needs to arrive in the sprint. If the rope is not located after testing, the upstream activities will inevitably congest testing and the WIP. The diagram here below shows the DBR configuration for a Scrum team with testing after development and appropriate ropes:
o PB and SB - the amount of needs inserted in the PB should not exceed a maximum thanks to 5S on the Backlog done on a regular basis in the PB
To improve your flow, Lean Management techniques should be involved such as Value Stream Mapping (VSM) [Poppendieck 2006] and other agile/DevOps techniques to spot improvement opportunities. For instance, to make testing more flow-compatible, we need to introduce some DevOps techniques:
The ToC is actually part of a wider scope of practices named PanTesting to scale agile testing.
Even if scripting test scenarios with Agilitest is rather lightweight since the tool is #nocode based [Forsyth 2021], automating scripts is something to take care of in terms of flow.
Traditional waterfall like organizations would delegate automation at the end of the SDLC which impedes the delivery flow. Introducing Lean/agile/DevOps techniques should improve your time-to-market and the First Pass Yield that goes along.