Some companies have admitted that not even all their mission critical systems will be fully ready. The effect of non-mission critical systems is often overlooked. Companies have rightly concentrated their remediation efforts on those systems that are essential to the operations of the business. However, the other systems must contribute something to the business or they wouldn't be there. Failures in these systems will have a negative effect on businesses and the economy.
Embedded systems are another problem area.
These are important in the control of many facilities and production processes. While it may be that only a small proportion of these systems have date problems, it is often difficult to identify and remediate those that do. Only an extreme optimist would expect that all of them will have been corrected. Segments of the economy such as manufacturing, retail, and service will be directly affected to the extent that firms in these sectors have problems. Lost production and sales will contribute to the decline in the economy.