The director, or designee, shall establish criteria which will comprise the basis for selection which shall include such factors as professional excellence, demonstrated competence, specialized experience of the firm, education and experience of key personnel, specialized staff capability, workload, ability to meet schedules and budgets, principals to be assigned, nature and quality of completed work, reliability and continuity of the firm, location, professional awards and other considerations deemed relevant. Such factors shall be weighted by the director, or designee, according to the nature of the work to be performed, the needs o the state and complexity and special requirements of the specific work.