Data Warehouse Decision Making

Author: Neville Turbit

Building Data Warehouses

It is surprising how easily the building of a data warehouse becomes confused because the real purpose is forgotten. The reason a data warehouse is constructed is to obtain information upon which decisions can be made. If the information is not used to make decisions, why are we collecting it?

Following on from this point, we can work backwards from understanding the decisions people make to determine what we need to store in the warehouse. The starting point is usually based around a person’s position description. It should outline what the role is able to influence. For example, a salesman will probably not be able to influence staffing levels. A sales manager may be able to influence levels. So what does the sales manager consider when determining staff levels? It may be number of customers in particular categories. It may be the number of service calls received. It may be the profitability of a particular group.

By understanding the areas a person or department can influence in the organization, it provides a path to work backwards to the data they can use to make those decisions. Below is a list of questions to ask potential users of the system. It is a data warehouse checklist.

Data Warehouse Methodology

In order to understand the way in which we might construct a Data Warehouse, we would like to focus on the sorts of influence you have on the way this Area operates. Starting from a high level:

1 Corporate/Branch/Section Focus �

What are the corporate objectives that are addressed by this area?
What are the Branch objectives that are addressed by this area?
Why does your Section exist?
What does it do?
What delegations does the section have?
How does that translate into how the Branch and Section operates?
What part does your Section or Branch play in the operation?
What parts of the business is your section responsible for, or do you influence?
Are there any parts of the business that influence your area but over which you have no control
Based on what you said were the objectives for the Branch and Section, are there any other areas you influence?
Are there functions that you carry out that are outside the Corporate, Branch or Section objectives?

2 Your Role

In terms of carrying out your work, what sorts of decisions do you have to make?
Are there other areas that you monitor or obtain information about?
What is this information used for?
Thinking about your job description, what parts of the business do you have responsibility for?
If you had to rewrite your job description, are there things you would put in the description that we have not covered?
What are they?
Are there other areas that impact on you but where you have no control but would like to have control?
What sorts of decisions happen in these activities?
What are your information needs in these activities?
Is there information you would like to have but is currently not available?
What would you do with this information? � Is your role similar to other people?
What are the things that make your role different to these people?

3 The Future

Are there things that could help achieve corporate objectives that you, or the department currently cannot, or do not do?
What sorts of decisions would happen in these activities?
What information would be required?
Are there developments in the department or externally that are likely to have an impact on how the area operates?
Will these cause new decision areas to emerge?
What additional information will be required to make these decisions?
� Will any of these cause new information to emerge?

4. Outside Influences

Are there external organisations or agencies with which you deal?
Do you provide them with information?
What do they do with the information?
Do external agencies provide you with information?
What do you do with the information?
Are there external organisations with which you deal who we would like to either receive, or pass on information to?
Are there external agencies who have an influence on the how we operate?
What influences the way in which we/they work?

NOTE: In terms of asking questions about decisions or activities people may carry out, it is important to follow up with a question about what they require to monitor to undertake that activity successfully