The following interpretation can be made:
As an extension of the experiment, de-aliasing of the effects would be imaginable and aleviate the doubts, provided 8 more samples.

Discussion and conclusion

On the thermal/humidity side, the plot of relative half effects (Figure 5) shows that the range of cycling has a more detrimental effect on the device's  lifetime compared to the mean temperature. This is an interesting finding, since that could imply that failure could be more likely linked to thermal fatigue phenomena, rather than a purely Arrhenius-based accelerated aging. Humidity (through "Dryness") is the second most important factor in this part, which shows a positive impact on the lifetime (as expected for MEMS):  lower is the humidity, longer is the live of the device. Dryness, Mean temperature and Range of cycling are most likely correlated.  Interestingly, the number of cycles -- within the frame of this experiment --  does not appear as a predominant factor. Surprisingly, the greater the number of cycles, the greater the lifetime. This outcome is consistent with the fact that a polymeric packaging filled with a damping gel should degrade faster compared to the ceramic/metallic counterparts. Has  to be noted that a full scale reliability study (50 cycles) would maybe bring to a different result. Finally, the normal plot indicated that, most likely, none of these factors is random.
On the mechanical side, the global view shows that all of the three factors (peak acceleration, maximum frequency and vibration sweeps) have big impact on the lifetime. The acceleration peak of vibration is slightly more detrimental than the maximum frequency. On the other side, the increasing number of cycles seems here to also increase the lifetime of the device.  A second run of experiments would maybe contradict this statement. 
Despite the normal plot indicating that most of the points are not normal, the model with interactions cannot represent correctly  the experiment, as shown by the large values of the residues. Nevertheless, a better knowledge of the outcome of a multi-parameter reliability assessment has been obtained. It would now be interesting, as future development, to extend the test plan with a focus on the most severe effects, increase the number of cycles and possibly apply the fractional factorial design.

References

[1] Swiss Center for Electronics and Microtechnology (CSEM), Technical Memorandum: Test programme for reliability assessment of MEMS products, 2016.
[2] J.-M. Fuerbringer, Design of Experiments (Doctoral Program  in Robotics, Control and Intelligent Systems), 2016.
[3] NIST/SEMATECH e-Handbook of Statistical Methods, http://www.itl.nist.gov/div898/handbook/, consulted in January 2018.