From this, we can tell if the application is a candidate for migration and start developing a project definition. Issues we may find include data quality of the current system, its historical availability and cost of service, and security. Older systems often have issues with system availability, scheduled or unscheduled for instance they are not so likely to support Web or global 24/7 needs. There also may be difficulty in use, such as high training costs or data entry error rates. A common strength of existing systems is that the system is paid for and the current staff is trained in its use. However, over time costs of security and maintenance may have crept up, and most systems have periodic maintenance and upgrades. Some companies outsource because these types of costs have gone out of control. Development productivity is commonly an issue with older systems, making it difficult to respond to changes in the business or to access data in new ways. Development activities in old complex systems often have remarkably little connection with current customer priorities.