Project Risk Management Oracle Tips  by Burleson Consulting

The Data Warehouse Development Life Cycle

Risk Management And Data Warehouse Projects

Data managers must always be cognizant that estimates of resources for a data warehouse project are only estimates, and that a certain element of risk is involved in any estimation. In the following example, you can see that the addition of human resources to a specific programming task has been estimated. You know, of course, that each marginal resource assigned to a project will increase the costs, and you can also safely assume that at some point, adding another resource will increase costs, without necessarily improving delivery dates (see Figure 2.7).

Figure 2.7 Risk and project management.

As you can see from Table 2.6, the data warehouse project manager must understand how to add additional human resources to a task in order to maximize delivery time. Just about any task that falls in the critical path of a project can be crashed by adding more resources, but, as mentioned earlier, there is a point of diminishing returns. This concept is especially true for data warehouse development, because many programming tasks cannot easily be partitioned into pieces that can be concurrently developed.

Resources                   Time                Cost
Joe                            7 days             $700 (Best for a non-critical task)
Joe and Francis            5 days             $800
Joe and Sam                4 days             $900 (Maximum crash point)
Joe, Sam, and Francis   4 days              $800

Table 2.6 A comparison of resources to assign to a specific task.

The project manager must also be able to make conscious tradeoffs when assigning programming resources to data warehouse tasks. As you can see in Table 2.7, there is often a tradeoff between programmer experience and programmer productivity. The real test is to weigh the additional costs for experienced programmers with their productivity. Table 2.7 demonstrates that while experienced programmers may cost more than naive programmers, they are often a better investment.

Years Of Experience              Rate           Lines/Day          Cost/Line
1                                       $20            10                   $2.00
3                                       $30            20                   $1.50
5                                       $40            40                   $1.00
7                                       $50            80                   $0.62
10                                     $60            160                  $0.38
12                                     $70            300                  $0.23
15                                     $80            400                  $0.20
Table 2.7 A comparison of cost per line of computer code.

The point here is very simple; the duration of a task is a function of both the amount of resources allocated to the task and the productivity of the resource that has been assigned to the task.

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This is an excerpt from "High Performance Data Warehousing", copyright 1997.

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