Information Systems Plans (ISP) are essential for any well-ordered enterprise. It is not uncommon for a business information system of import to the business to take very significant resources in terms of money and time.
The basis for dimensioning this issue and for the computation of traditional approach costs and changed approach costs and finally the determined ROI is based on a "rule of thumb."
The size and cost of a business information system is based on the count the quantity of third normal form database tables, which is then multiplied by 80 to get the total of function points. That result is then multiplied by the function point cost, which can range from $200 to $400 (depending on the mode of traditional implementation) to get a ball-park estimate for the business information system.
Thus, if a database has 200 tables, the function points is 16,000, and the ball-park cost, at $200 per function point, the cost of a single business information system is about $3.2 million.
Many enterprises have 20 to 50 major business information systems. Thus, the total implementation cost of just the business information systems inventory is about $64 million.
Given that this is not a small amount of enterprise resources, which business information system should be done first? Which leverages the other? What role does an enterprise data model play? How and what kind of business drivers are important in determining the sequence? How can you develop an information systems plan in an efficient, cost-effective, repeatable, and maintainable form?
Traditionally developed business information systems plans as set out by the IBM, James Martin, and Clive Finkelstein approaches are all very laborious. That is because each approach contains steps that require between 30 to 40 thousand staff hours over multiple calendar years.
These traditional approaches would, if having no information systems plans were analogous to a disease, have the patient die from the cure well before the disease.
The three major components of these approaches is the construction of fully attributed third-normal-form data models, a fully developed, enterprise-wide detailed function model, and a full cross reference between these two models in terms of Create, Read, Update, and Delete (CRUD).
While each is important during the development of actual business information systems, they are profound over-kill when planning for the sequence and cost of business information systems. The Whitemarsh paper, Engineering and Managing Information Systems Plans, set out the traditional approaches, their costs, and the very significant drawbacks.