CTFL 2.1.5: Explain shift left

• ✓
  Correct answer: Begin non-functional testing at the component test level wherever that is possibleMoving non-functional testing down to component level is a named shift-left practice.
• b
  Run the full regression suite immediately after each release to productionTesting after release moves activity later, which is the opposite direction.
• c
  Complete the static analysis of the source code only once dynamic testing has begunStatic analysis should be completed prior to dynamic testing, not after it starts.
• d
  Assign a dedicated independent test team to the later test levelsStaffing the later levels moves no test activity earlier in the SDLC.

Performing non-functional testing starting at the component test level, where possible, is named among the good practices that achieve shift left, precisely because these non-functional test types tend otherwise to be performed late in the SDLC when a complete system and a representative test environment are available — which is the situation described.

Syllabus section 2.1.5

• a
  Because shift left applies only to static testing, which cannot replace dynamic testingWriting test cases before the code and running them in a test harness is also shift left.
• b
  Because shift left requires all testing to be completed before implementation beginsTesting earlier does not mean all testing finishes before implementation.
• ✓
  Correct answer: Because shift left means testing earlier, but explicitly not neglecting testing later in the SDLCEarlier testing does not license neglecting the later testing.
• d
  Because shift left is another name for the whole team approach rather than for early testingShift left is another name for the principle of early testing.

The principle of early testing is sometimes referred to as shift left, because it is an approach where testing is performed earlier in the SDLC. Shift left suggests that testing should be done earlier — for example not waiting for code to be implemented or components to be integrated — but it does not mean that testing later in the SDLC should be neglected.

Syllabus section 2.1.5

• a
  The rise shows the adoption failed, since shift left should reduce effort immediatelyAn early rise is what the syllabus predicts, not a sign of failure.
• b
  The rise is unrelated to shift left, which only reorders work that was going to happen anywayThe syllabus expects a real early increase, not merely a reordering.
• c
  The early costs should be recovered within the same phase in which they aroseThe saving is expected later in the process, not within the same phase.
• ✓
  Correct answer: Extra training, effort and costs earlier are expected, with effort and costs saved laterHigher cost early, with the saving expected later.

Shift left might result in extra training, effort and/or costs earlier in the process, but it is expected to save effort and/or costs later in the process. A rise in early effort and training cost is therefore the predicted pattern rather than evidence of failure. It is also important that stakeholders are convinced of and bought into the concept.

Syllabus section 2.1.5