徹底 and 一貫: thorough execution and a consistent direction
Compare thorough cleaning or checks with a consistent stance or use of colour, separating the scope of execution from a maintained direction.
Thorough execution with 徹底
徹底 (てってい) refers to thorough execution of an action or procedure. The example 「道具の使用後は清掃を徹底している。」 is translated as “We clean the tools thoroughly after use.” Read thorough cleaning after use as the stated practice and scope.
The example 「安全確認を徹底するよう全員に求めた。」 is translated as “We asked everyone to perform safety checks thoroughly.” Everyone is asked to carry out safety checks thoroughly. The request does not report that everyone has completed them.
A maintained direction with 一貫
一貫 (いっかん) refers to consistency across a period or whole. The example 「彼女は最初から最後まで一貫して反対した。」 is translated as “She remained consistently opposed from beginning to end.” The opposing stance remained from beginning to end. Whether that stance was correct is a separate assessment.
The example 「作品全体に一貫した色使いが見られる。」 is translated as “The use of color is consistent throughout the work.” Read the consistent use of colour across the work. It does not require a single colour or identical parts.
Separate thoroughness from consistency
徹底 concerns sufficiently thorough checking or cleaning; 一貫 concerns a stance or direction maintained across a period or whole. Thorough execution does not necessarily establish a consistent stance.
Separate the request for thorough safety checks from completed checks. Likewise, a stance maintained from beginning to end does not report that cleaning or checking was carried out thoroughly.
What different axis appears in requesting everyone's 徹底 of safety checks and remaining 一貫して opposed from beginning to end?
Show the answer and why
The first requests thorough execution of checks; the second reports a consistent opposing stance across the period. Do not add completed checks from the request or merge thoroughness with consistency.