ERP, or enterprise resource planning, is software that enables business processes in the finance, manufacturing, distribution, sales and other areas. Extended ERP includes other software and business processes. Integration with ERP is usually required to eliminate redundant information and processes. Software sold and supported as integrated may reduce ongoing maintenance costs.
Customer Relationship Management
Customer relationship management, or CRM, includes software related to business processes for sales force automation and call centers. ERP and CRM require minimal integration.
Product Lifecycle Management
Product lifecycle management software may include design, regulation, manufacturing, distribution and field service activities having to do with how a product changes over it's life cycle. Depending on the industry, PLM software may cover more business processes or be restricted to design and engineering functions.
Supply Chain Management
Supply chain management may include software for planning and controlling any step in the manufacturing and distribution process, including tracking external companies' handling of products. SCM may also include logistics and warehousing business processes.
Depending on the industry and functionality requirements, ERP, CRM, PLM and SCM will require different degrees of integration. If the software is acquired in an integrated fashion, these costs are reduced. If extensive, these integration costs may continue to be an issue when any one software area is upgraded by the original vendor. Extended ERP may include more software and processes depending on the industry served.