The potential significance of SAP's Investment Management module (IM) is too often overlooked when considering the management of complex enterprise projects. Nevertheless it should in most cases be considered when designing scalable project management solution that center around SAP.
SAP IM is a tool designed to enable program management in SAP. Program management as defined by SAP in that context means the process of defining a hierarchy on top of many projects with the purpose of planning and controlling costs, including project appropriation management and budget authorizations. Its strongest integration points, besides PS, are with the SAP Controlling (CO) and Asset Management (AM) modules.
While IM was originally developed for the budgeting and high-level management of capital investment initiatives, its functionality has been extended to allow its use for similar functions. It simply is a tool that can perform such functions on top of any kind of PS projects.