BB field complex redevelopment is an integrated development under PETRONAS Enhanced Oil Recovery (EOR) project. BB fields are producing fields operated by PETRONAS Carigali Sendirian Berhad (PCSB). The BB fields redevelopment is a project to redevelop both B1 and B2 fields and to enable EOR implementation in the B1 field. The B1 redevelopment includes the EOR implementation through immiscible water alternating gas (IWAG), infill drilling, and safeguarding of no further activity (NFA) production. The B1 redevelopment also incorporates some provisions for the B2 field to secure gas supply for B1 IWAG. The B2 redevelopment focuses on safeguarding B2 NFA production. The redevelopment consists of three main elements, 1) EOR IWAG that involves injector well drilling at a new IWAG injection wellhead platform, 2) infill drilling at existing platforms and 3) safeguarding of NFA. Surface facilities scope includes installing a new Central Processing Platform (CPP) for B1 field, wellhead platforms, and intra-field pipelines. The CPP includes 60 kbpd water injection plant capacity, gas compression, gas-liquid separation, and produced water treatment. Modification in the B2 field is to flow gas from the B2 field to the B1 field. Operational readiness is crucial to ensure that the integrated project is executed smoothly. Two cases for changes are new technology deployment for water injection module (WIM) and people capability. It is a big challenge to achieve an effective start-up with minimum delay. There are some important aspects considered includes operation philosophy, Health Safety and Environment (HSE), and collaborative working environment (CWE) implementation. It is important to ensure improving oil recovery through infill and IWAG. Best practices in operation readiness of an integrated project that have many challenges that include process, people, and technology. These best practices may be replicated in any other projects by other companies/operators.