Data Warehousing - Data Warehouse Team Selection

There are two areas of discussion: First is whether to use external consultants or hire permanent employees. The second is on what type of personnel is recommended for a data warehousing project.
The pros of hiring external consultants are:
1. They are usually more experienced in data warehousing implementations. The fact of the matter is, even today, people with extensive data warehousing backgrounds are difficult to find. With that, when there is a need to ramp up a team quickly, the easiest route to go is to hire external consultants.
The pros of hiring permanent employees are:
1. They are less expensive. With hourly rates for experienced data warehousing professionals running from $100/hr and up, and even more for Big-5 or vendor consultants, hiring permanent employees is a much more economical option.
2. They are less likely to leave. With consultants, whether they are on contract, via a Big-5 firm, or one of the tool vendor firms, they are likely to leave at a moment's notice. This makes knowledge transfer very important. Of course, the flip side is that these consultants are much easier to get rid of, too.
The following roles are typical for a data warehouse project:

Project Manager: This person will oversee the progress and be responsible for the success of the data warehousing project.

DBA: This role is responsible to keep the database running smoothly. Additional tasks for this role may be to plan and execute a backup/recovery plan, as well as performance tuning.

Technical Architect: This role is responsible for developing and implementing the overall technical architecture of the data warehouse, from the backend hardware/software to the client desktop configurations.

ETL Developer: This role is responsible for planning, developing, and deploying the extraction, transformation, and loading routine for the data warehouse.

Front End Developer: This person is responsible for developing the front-end, whether it be client-server or over the web.

OLAP Developer: This role is responsible for the development of OLAP cubes.

Trainer: A significant role is the trainer. After the data warehouse is implemented, a person on the data warehouse team needs to work with the end users to get them familiar with how the front end is set up so that the end users can get the most benefit out of the data warehouse system.

Data Modeler: This role is responsible for taking the data structure that exists in the enterprise and model it into a schema that is suitable for OLAP analysis.

QA Group: This role is responsible for ensuring the correctness of the data in the data warehouse. This role is more important than it appears, because bad data quality turns away users more than any other reason, and often is the start of the downfall for the data warehousing project. The above list is roles, and one person does not necessarily correspond to only one role. In fact, it is very common in a data warehousing team where a person takes on multiple roles. For a typical project, it is common to see teams of 5-8 people. Any data warehousing team that contains more than 10 people is definitely bloated.