The analysis and improvement for IEC706-6-94 maintainability allocation method

Maintenance time allocation is an important work in maintainability design. It is important to consider allocation with the MACMT and ACMT(95) for subitems. The paper gives the introduction of a graphic method and an improved analytic means used in maintainability allocation. The ICE60706-6 gives the value of ACMT(50)/MACMT by looking up the graphic. However man-error could be induced using the method, so the value is often not accurate. The improved analytic method provides analytic expression of maintenance time allocation, which avoids the man-error induced by graphic method. According to the log-normal distribution (with lower sigma), the method can give the expression of f{(ACMT95)/(MACMT)} the IEC60706-6 doesn't provide. So it is more convenient for CAD, more convenient and accurate to do allocation.