To deliver operational results, many business processes are tightly connected to the IT infrastructure. The telecom sector is an example where this is especially true. The mobile voice operations are very critical for a telecom provider. Read on to know how HCL ran these business critical operations for a leading telecom provider in Belgium. Enterprise IT Application Services can be divided into RTB and CTB services. While RTB or “Run the Business” services include Application outsourcing which is basically Application support and Maintenance, CTB or change the business services are new information technology implementations to change the way you do your business. The RTB application support and maintenance has traditionally been a low value adding activity taking up a lot of SME bandwidth as well as heavy costs. Traditional Application support and maintenance practices - whether they are carried in-house or are outsourced – do not aim at reducing ASM costs and impacting business performance. The document explains the success factors of a successful mission critical application outsourcing relationship. Belgacom recognizes an increasing demand for quality in mobile voice. The increased dependency on mobile phones also means that consumers expect to be connected to the network at all times. Non-performance reflects immediately on the corporate brand of the company. Because failures of the network have an immediate impact on the customer perception of Belgacom, management indicated that the number of ‘high priority incidents’ needed to be reduced to a minimum. For reasons of financial optimization, Belgacom decided to outsource mobile voice operations and the running of the associated infrastructure. A thorough due diligence took place to determine the right vendor and to make sure that HCL – the selected partner – was up to the challenge. HCL took over the responsibility to run the mobile voice platform and the two companies have been cooperating for the past five years now. Running of such business critical process chains is not easy for both the IT service provider and the outsourcer. Business IT Alignment, Trust and a healthy relationship, Engagement Flexibility, agility achieved through flexible staffing, proactive improvements are some of the principles that should be adopted by both the service provider and the outsourcer/ client to achieve the success of such a relationship. Conclusions: what it takes to make a partnership work Outsourcing a business critical platform asks for a partnership approach and it works for both Belgacom and HCL. Organizations with little outsourcing experience often expect that success of the relationship lies solely within the hands of the service provider. More mature organizations often experience a lack of control; they feel it is almost impossible to influence their service provider. What can they learn from this specific case?