Software Project Estimation and Planning Strategies

Risks Inherent in the Estimate

• Complexity of the project: Always relative, as it is affected by our familiarity with the subject.
• Project size: The larger the project, the greater the risk of the estimate.
• Degree of uncertainty.
• Availability of historical information: Without data from previous similar projects, uncertainty increases.

Resources Planning

An important aspect of project planning is estimating the resources needed. These resources are categorized into three types:

1. Infrastructure or development environment: Hardware and software that support the development effort.
2. Software components: Reusable assets that significantly reduce development time and cost.
3. People: Personnel needed for the project.

For each resource, it is necessary to specify:

• Description of the resource.
• Report on availability.
• The chronological date the resource is required.
• The duration for which the resource will be used.

Estimation Technique Based on the Problem

• Defining the scope.
• Resolving the software, which may involve individual estimates.
• Estimating LDC/PF for each function.

Estimation Technique Based on the Process

• Defining the scope.
• Resolving the problem functions (parts of the process) and performing a number of activities for each.
• Once activities and functions are combined, the planner estimates the effort.

Objectives of the Plan

The purpose of project planning is to provide a framework that allows the project manager to monitor various activities and tasks. This framework should be adapted as the project progresses.

Scope of Software

To realize software project planning, it is necessary to understand the scope, which is determined by:

• Functions: The features the software must implement (decomposition is often useful).
• Performance: Expected response time and processing capabilities.
• Restrictions: Hardware, communications, or scheduling constraints.
• Interfaces: Requirements for connecting to other systems.
• Reliability: The degree of reliability expected of the system.

Software Project Estimation Options

For the realization of estimates, we have the following options:

• Delaying the estimate: This is never recommended.
• Basing it on previous similar projects: Usually yields good results if influences are accounted for.
• Using decomposition techniques: Relies on the principle of "divide and conquer" to estimate more easily.
• Using empirical models.
• Using automatic tools: Often implement decomposition techniques and empirical methods.