Posts tagged ‘example’

Table of contents for Project Estimation Model

  1. Project Estimation Model
  2. Project Estimation Model Example
  3. Project Estimation using Scenarios

Defining estimation scenarios

The first stage in the steps to estimating a project was defined to be the definition of the scenarios to be supported in the solution.  The scenarios should be defined at as low a level of detail as possible, with the following diagram showing the example scenario definition.

Scenario definition

Scenario definiton

Definition of the scenarios sizing

Continue reading ‘Project Estimation using Scenarios’ »

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Table of contents for Project Estimation Model

  1. Project Estimation Model
  2. Project Estimation Model Example
  3. Project Estimation using Scenarios

As a means for discussing the model I will follow through an example of the model being used. To do this the needs to be an example usage scenario. In this case I have chosen to use the following:

“A banking web site has retail and corporate clients, and well as a set of automated processes that must be completed overnight in the bank’s overnight batch window. The site has a standard Java web architecture, with the batch processes being initiated using a batch process at the application server. The purpose behind the model is to examine the capacity required in the major system components, and to make ensure the ongoing capability of the host systems for the site.”

If you have followed through the performance model series (here), you will note that this is exactly the same scenario. I have chosen this in order to be able to compare and contrast the application of the performance and project estimation models. There are clear differences in approach that need to be considered. For those that like to skip to the end I have provided a copy of the final estimation example filled out here:

Example project estimate

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Having defined the key system functions and the user population it is now necessary to define how the users place a functional demand on the system. (The online version of this article has more detail again.) The first part of this definition is to lay out how the usage of the system varies over time. Thus the relative usage of the system needs to be defined. The initial definitions are on an intra-hour, hourly, daily, weekly and monthly basis. These figures effectively have no units and simply provide a relative level of usage. Thus any metrics that are available to allow calibration of this data can be used. As an example, estimated percentage utilisation of the system for the time period could be provided. Alternatively, there may be historical data available from a production system. Continue reading ‘Example: Usage Definition’ »

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