Software development cost estimation guidebook

Use of these best practices should enable government programs to better estimate and manage their costs to improve program management and execution.

Developing reliable cost estimates is crucial for realistic program planning, budgeting and management. While some agency guidelines on cost estimating are thorough, other agency guidance is limited regarding processes, procedures, and practices for ensuring reliable cost estimates. The Cost Guide is intended to address that gap. The guide outlines key steps in the cost estimating process: the purpose, scope, and schedule of a cost estimate; a technical baseline description; a work breakdown structure; ground rules and assumptions; data collection; estimating methodologies; sensitivity and risk analysis; documenting and presenting results; and updating estimates with actual costs.

The guide also includes information on earned value management; the composition of a competent cost estimating team; software cost estimating; and best practices for an analysis of alternatives. But in actually the SCE process follows on cost driver factors i.

These factors are such as design methodology, memory management, experienced skills, hardware requirements, software tools, risk analysis, project complexity, project delay, size of project database, performance parameter, virtual memory environment, etc. Such as:. It is called the Constructive Cost Model, which is mainly used for software cost estimation i.

This model depends on the number of lines of code for software product development. It also estimates the required number of Man-Months MM for the full development of software products. So the model name shows as Expert Judgement Model. This model is used to estimate the effort, cost and development time for a software project which depends on a single variable. The relationship is given by:. This model is used to estimate the effort, cost and development time for a software project with depends on multiple internal or external variables I.

Effort Adjustment Factor cost driver factors. The software cost estimation is done for the new project by comparing the previous completed project estimation. The insight comes from experts in the fields of software development and cost estimating. A well-understood and validated estimate offers a defensible position for program office analysts, component cost agency analysts, and independent evaluators.

A reasonable estimate is useful in budgeting, milestone decision reviews, and determining the life cycle or other costs of the program. The contents of this volume, ten sections and nine appendices, are grouped into four major parts.

An introduction and the basics of the software development process lead off the tutorial. The next two parts cover the estimating process and related details. Concepts and examples presented in the sections are covered in greater detail in the appendices. The idea behind this structure is to present principles for instruction and reference in the core sections and, then, examine details and related examples.

The information herein is not intended to dictate policy or supplant guidance given in official documents.