Template:Growth potential design margin crow extended

Growth Potential Design Margin

The Growth Potential Design Margin ( [math]\displaystyle{ GPDM }[/math] ) can be considered as a safety margin when setting target MTBF values for the reliability growth plan. It is common for systems to degrade in terms of reliability when a prototype product is going into full manufacturing due to variation in material, processes, etc. Furthermore, the in-house reliability growth testing usually overestimates the actual product reliability, since the field usage conditions may not be perfectly simulated during growth testing. Typical values for the [math]\displaystyle{ GPDM }[/math] are around 1.2. Higher values yield less risk for the program, but require a more rigorous reliability growth test plan. Lower values imply higher program risk, with less safety margin.

During the planning stage, the growth potential MTBF, [math]\displaystyle{ {{M}_{GP}}, }[/math] can be calculated based on the goal MTBF, [math]\displaystyle{ {{M}_{G}}, }[/math] and the growth potential design margin, [math]\displaystyle{ GPDM }[/math] :

[math]\displaystyle{ {{M}_{GP}}=GPDM\cdot {{M}_{G}} }[/math]

or in terms of failure intensity:

[math]\displaystyle{ {{\lambda }_{GP}}=\frac{{{\lambda }_{G}}}{GPDM} }[/math]