Outsourcing is a huge industry, with outsourcing being used by small and large corporations with local and even international portfolios. There is a reason they are successful in getting the attention and the business from large sophisticated corporations.
While their success is based on some very specific advantages that are hard to reproduce in smaller organizations, if you aren't thinking of outsourcing, there are a number of practices you can introduce into your organization to improve your service delivery, improve efficiency and reduce costs.
Almost always part of outsourcing contracts focuses the outsourced provider's priorities and resources on the things that matter to you. An effective performance framework can also be applied to in-house delivery or subcontracted services.
First, establish your corporation's primary objectives and design performance measurements (Key Performance Indicators) to support those objectives. Translate these to the activities and services you deliver and establish measures, targets, reports and review processes. Use the results to spot trends or missed performance and implement changes to address problems with staff or subcontractors. Build these measures into your next round of procurement.
While some outsourcing companies are ISO certified, you don't need certification to apply the principles of quality assurance to your internal services or subcontractors. Start by learning the basis of Quality Assurance, which includes documenting processes and procedures, identifying inputs and outputs, key process elements, tracking and reporting, adherence to procedures and auditing. Apply these principles to your staff and subcontractors for improved results.
Quality Assurance itself doesn't ensure you are doing the right things, but once you establish best practices, it ensures they are followed. The best implementations enable innovation by your staff and promote continuous improvement of your processes.