In many mainframe shops - organizations using applications that run on the mainframe - senior management struggle with their isolated, expensive, complicated mainframe environment.  The mainframe investment is a significant part of your IT budget, needing to board-level decision making. It is unclear if the value of your mainframe investment is in line with its value. Mainframe applications are often core applications, deeply rooted in organizational processes. Business innovation capacity is limited by legacy applications and technology. Too much is spent on maintenance and continuity, too little on innovation. At the same time, the misalignment increases. The organization moves to a cloud model for their IT - what is the mainframe position in that respect? The mismatch between Enterprise Architecture and mainframe landscape is increasing. Organizational and technical debt is building up in the mainframe environment, maintenance and modernization are postponed and staff is aging. A decision must decide whether to throw out the mainframe legacy or revitalize the environment, but they have far from complete information to make a good judgment. Divestment options Let's look at the divestment options you have when you are stuck in this situation. Rehost the platform, meaning, move the infrastructure to another platform or to a vendor.  This solves a small part of the problem, namely the infrastructure management part. Everything else remains the same.  Retire all applications on the mainframe platform. Probably the cleanest solution in the divestment strategy. However, this option is only viable if replacing applications is available and speedy migration to these applications is possible. Replace through repurchase, meaning replace your custom solution with another off-the-shelf solution, whether on-premise or in a SaaS model. This is only an option if, from a business perspective, you can live with the standard functionality of the package solution.  Replace through refactoring is an option for application where special functionality support distinguishing business features that can not be supported in off-the-shelf applications. Significant development and migration efforts may be needed for this approach. A total solution will likely be a combination of these options, depending on application characteristics and business needs. The investment option The Investment option is a stepwise improvement process, in multiple areas, depending on the state of the mainframe applications and platform. Areas include application portfolio readjustments, architecture alignments, application and infrastructure technology updates, and processes and tools modernization. Depending on the state of the environment, investments may be significant. Some organization have neglected their mainframe environment for a decade or longer, and have a massive backlog to address. In some cases the backlog is so big, that divestment is the only realistic option. (As an example, one organization needed to support multiple languages, including Chinese and Russian, in their business applications. After 10 years of maintenance neglect of the middleware, the only option they had was to abandon their strategic application platform. This brings excessive costs, but more important for the organization's competitiveness, technical debt hits at the most inconvenient moments.) To find the best option for your organisation you should consider…