GPPB NPM 160-2012 answered this question, to wit:
Qualifications of Alternate Members of the BAC
As regards your query on whether a fifth ranking permanent official may be designated as an alternate to a regular BAC member who is fourth ranking permanent official, we refer to Section 11.2.4 of the IRR of RA 9184, which provides that the HOPE may designate alternate members to the BAC, who shall have the same qualifications as their principals as set in the Act of this IRR.
Based on the foregoing provision, the phrase "the same qualification as their principals", should be understood together with the clause "as set in the Act and this IRR". This means that the qualifications used in determining the principal are the same qualifications used in determining the alternate BAC member. As such, an alternate BAC Chairperson and an alternate regular BAC member should be at least third ranking and fifth ranking permanent official of the PE, respectively.
In sum, we are of the view that it is the plantilla position in the organizational structure of the PE that determines whether an official is eligible to become a member of the BAC. In addition, alternate members of the BAC must have the same qualifications as their principals as provided in Section 11.2.4 of the IRR of RA 9184.
In short, the BAC or any of its alternate member is determined based on the plantilla position in the organizational structure (ranking) not their civil service qualification such as atty., dr., CESE but their ranking from the HOPE. If the equal of the Atty. III in the Organizational structure is assistant director or division head as long as they are in the same organizational structure ranking then they are qualified.
