We have to ensure zero downtime on any system upgrade now a days if it's purely legacy system then we have to intimate every stakeholders well in advance with the outage window & proper planning with post production migration. Team should perform UAT in a replica environment for minimising any unforseen challenges post go live. Take necessary snapshot & back up of your data into separate instance to prevent any data loss during this upgrade.

é importante estabelecer uma comunicação clara e regular com as partes interessadas. Isso envolve compartilhar o cronograma do projeto, atualizações de progresso e qualquer risco ou mudança significativa que possa ocorrer. Realizar reuniões periódicas, fornecer relatórios detalhados e manter canais abertos para perguntas e feedback ajuda a construir confiança. Garantir que as expectativas estejam alinhadas desde o início, e fornecer um plano de contingência para possíveis problemas, também fortalece a relação de confiança e garante transparência ao longo do processo.

Various project management tools can be employed to keep the project in line with the schedule, like Jira, Microsoft Project, Teamwork, etc. ... The other major factor that can be used is simple communication. To keep the internal hierarchy abreast of the project status and to establish a rapport with the client. Keeping the client updated weekly through presentations and documentation that provides the information they need to project their timetables within their organization.

To maintain transparency and trust during a system upgrade, ensure minimal downtime by carefully planning and communicating any necessary outages in advance. Provide regular updates on schedules, impacts, and benefits, and keep communication channels open for feedback. Conduct thorough testing in replica environments and implement robust data backups to prevent data loss. Involve stakeholders in testing and decision-making, highlight tangible benefits like increased efficiency and cost savings, demonstrate early successes through pilot programs, and openly address potential risks with clear mitigation strategies. This approach keeps stakeholders informed and confident throughout the upgrade process.