Database Design Documentation

Functional SpecificationIt is often the case that a company knows that they need a new system but do not know what they actually require to run their business to increase productivity and efficiency.

If after our intital free visit, AV Computer Services (UK) Ltd are unable to gather enough information to be able to suggest a system build, we are able to suggest the development of a full System Functional Specification.

A full system specification would give you a complete document showing you a clear picture of the system that you would require to be developed, built to your own unique business processes.

The purpose of the system functional specification is to allow you to be able to either build your new system yourself (if you have the technical inhouse expertise) or alternatively pass this document to any Database Development Company who would be able to build your system from this document.

Although a system functional specification is primarily a document that gives you clear and concise details of the functionality that is expected to be achieved by the resultant system that is built, any functional specification developed by AV Computer Services (UK) Ltd would also give you all of the technical components that would allow your system to be built.  However, although we would recommend various technologies within the specification, it would be laid out in such a way that any developer would be able to take this document and build you a system in any other suitable technology should you so require.

The main components of the system functional specification would be as follows.


This section of the functional specification would give a brief background as to the reasons for requiring the database and the purposes behind the system to be developed.

Change Log

This section would detail each revision of the function specification document.

Applicable Document List

This section would list any documents which are referenced in order to produce a working database to achieve a system that fits the needs and wants of the client.

System Requirements

This section would give details of any technical requirements for the system to be built.  In general this would detail the minimum operating system requirements, the development platform in which the system will be developed and the end user software requirements that would be necessary for the system to operate correctly.

Relational Diagram

This section of the functional specification would lay out the way in which all of the tables designed to hold the data would talk to each other giving a clear view of the overall structure of the database.

Table Definitions

This area of the system specification would give full and complete details of each table that would need to be developed giving each column (field) including their Name, Data Type, Description and any Key i.e. whether the column is to be used as a primary or foreign key.

Business Rules

This part of the system specification would detail any specific business rules which must be applied to the data.  For example, do not show a customer record in the main screens for selection if the client has been flagged as dormant.  Normally these business rules are already defined by your business practices but are very often, not actually documented anywhere as they are automatically carried out by the employees as a matter of course.

User Interface

Once the data structure has been laid out, we would then give details of how we expect the user interface to be laid out. This would take the form of descriptive details for each of the user entry points to the data together with rough screenshots of the look and feel of the finished user interface.  These screens however, would only be a rough interpretation and would be subject to artistic license when the actual system development took place depending on any development issues encountered during development.


The final section of the functional specification would be to record the reporting requirements that would need to be achieved from the resultant database.  this section would list each required output together with a brief description of their selection criteria, grouping and display columns.


In order to carry out a full system functional specification, AV Computer Services (UK) Ltd would need to spend at least a couple of days at your business gathering your requirements from your key users and then would spend several days at our own office writing up the actual document.

Since there may be various changes required by the client during the life cycle of the functional specification, all changes would be detailed by way of an official change request document.

Depending on the size and complexity of the project, the functional specification may go through several versions before the final document is signed off.  However, once the final document is signed off, this would give any developer the complete picture to enable them to design your system for you.

Since it depends on the size and complexity of the database development that is required, it is impossible to give a fixed price on the development of a system functional specification, however, the average document normally takes around 5 days (2 days with the customer and 3 days writing up) for the initial draft to be completed.  Any change requests would then incur further cost to change the functional specification accordingly. 

Take The Next Step.

To find out more about how we can help you with one of our System Functional Specifications, give us a call on 01536 264220 or go to our Contact Page.