When discussing design alternatives and their effects as part of a design approach, key factors to consider generally include cost, performance, and security. These factors help to evaluate the viability and impact of different design options. Cost is crucial for budgetary considerations and feasibility. Performance addresses how well the design meets the required operational criteria and efficiency. Security ensures that the design protects against threats and vulnerabilities. Other options such as backup and knowledge, while important, are not typically primary factors in a design approach discussion.