When vendors make unrealistic promises, it's crucial to manage expectations and maintain control. Begin by 1. Clearly define the project's scope, timelines, and deliverables upfront, ensuring all stakeholders are aligned.Request detailed, written commitments from the vendor, outlining customization capabilities and support. 2. Break the project into manageable phases with regular check-ins to monitor progress. If promises seem overly ambitious, push for proof-of-concept or pilot testing to verify feasibility. 3. Collaborate closely with your internal team to identify potential risks /gaps. 4. By maintaining transparency, setting clear expectations & holding vendors accountable, you can ensure realistic and successful customization.

Lorsqu'un fournisseur n'a qu'un seul point d'entrée qui fait des promesses iréalistes, et que ce point d'entrée masque des litiges internes et des priorités non gérées chez le fournisseur, il ne faut pas s'engager trop fort et accepter les conséquences possibles de l'échec du fournisseur. En revanche si le fournisseur a plusieurs points de contact variés et de qualité pour chaque grande fonction de l'entreprise, alors lui faire plus confiance ...

Hopefully you inherited such a mess rather than creating it. There are two aspects to address: 1) There is the fundamental question of "Why are the promises unrealistic?" and 2) There is the immediate concern of the current promises. I am sure others will focus on the immediate concern so I will focus on the long term question. Unrealistic promises may be naiveté, lack of experience (e.g. innovation), a perception of what you will accept as a bid, estimation of what competitors will promise, etc. The reason it is important to drill down is that you need to be surrounded by strategic partners who you can trust. The mechanics others will address in point 2 above are an overhead you can't afford long term.

Clear Requirements Definition: Start by clearly defining and documenting your requirements. This helps in setting realistic expectations and ensures that both you and the vendor are on the same page1. Vendor Evaluation: Choose your vendor carefully. Look for vendors with a proven track record in custom software development and check their references. It’s also beneficial to evaluate their technical expertise and project management capabilities2. Agile Development Methodology: Adopt an agile development approach, such as Scrum or Kanban. This allows for iterative development and regular feedback to ensure the project stays on track. Effective Communication: Maintain open and regular communication with your development team.