The first step to establishing a supplier certification program is to

Establishing a clear purpose, scope, and responsibilities is the foundation of any successful program, including supplier certification. This ensures alignment, ownership, and effective implementation.

Developing a requirements manual (A) and establishing an audit schedule (B) are critical steps, but they come after the initial program framework is defined.

Identifying existing suppliers (C) is part of the broader supplier selection and evaluation process but doesn't establish the certification program itself.

References:

ASQ CMQ/OE Handbook, Section VI: Quality Systems (emphasis on program planning and management, including defining objectives and responsibilities)