Firms are turning to service-oriented architecture (SOA) for cost-effective flexibility and enhanced usage of legacy IT. But the shift to SOA doesn't come easy and doesn't come cheap. Building an effective SOA platform requires tight integration between new and existing product categories, and it may require large investments for new products such as SOA repositories. As few firms can shell out the funds for a complete transformation all at once, Forrester recommends placing tactical SOA investments in a planning framework for evolving to a strategic SOA platform.