The conditions for the application of this standard are stated in JIS Z 9041-2. That is, the test method considered here is valid when the measured variables are assumed to be normally distributed in each population. JIS Z 9041-2 is concerned only with type 1 hazards (or significance levels). This standard recommends how to judge Type 2 hazards and the detection power of assays.
JIS Z 9041-4:1999 history
1999JIS Z 9041-4:1999 Statistical interpretation of data -- Part 4: Power of tests relating to means and variances