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Cost Estimation Toolkit (CET) Software Package

The Cost Estimation Toolkit(CET) is designed to provide NASA budget estimators, PIs, project managers, and resource planners with the capability to generate life-cycle cost estimates for implementing, operating and maintaining a science data system. The CET provides output in spreadsheet and graphical formats, and has various tools for what-if options, output review and manual override, parameter sensitivity tests, and creating new or updated historical project data in the Comparables Database (CDB). Users interface to the CET through Visual Basic developed forms that provide the inputs to Microsoft Excel where cost estimates and various output functions are generated. The Toolkit runs on PC or Mac platforms.

Cost Estimation Toolkit (CET) Goals

The CET is an Excel Visual Basic for Applications (VBA) application. As such the software is contained in an Excel workbook and includes VBA modules and user forms. Each VBA module includes a number of procedures (equivalent to subroutines) and the user forms are Excel programmable user interface features that include VBA procedures. The CET also includes worksheets used for a variety of purposes. These include the Activity Datasets entered and maintained by the user. Three worksheets contain the output of the CET; two contain the life cycle cost estimate for a user-described data activity and a third contains a ‘quality report’ to help the user decide how much confidence he/she should place in the estimate. Another worksheet contains the Activity Dataset Checklist that contains information describing all of the information that a user must enter for each applicable functional area to describe a data activity to the CET. Also included are a set of worksheets that are internal to the CET, e.g., used for display backgrounds and to hold intermediate results. The CET also accesses the Comparables Database (CDB), a separate Excel workbook that contains worksheets for the data activities (historical projects) whose information comprises the CDB.

The objective of the effort estimation process is to produce, for a new data activity, year-by-year estimates of operational, technical, and management staff effort for each functional area applicable to the new Activity Dataset. Functional areas include: ingest, processing, documentation, archive, access and distribution, user support, sustaining engineering, engineering support, technical coordination, implementation and facility /infrastructure. The effort is expressed in Full Time Equivalents (FTEs), the effort equivalent to that of a single person working full time for a year.

The effort estimate for each functional area for a new data activity is based on its planned workload in that functional area, and the relationship between workload and staff effort observed in existing data activities in that same functional area. The workload and staffing information for each functional area for existing data activities is contained in the CDB.

For each functional area, the primary effort categories, technical and operational, are each assumed to be a function of a particular combination of workload parameters (e.g., data volume, number of products). The relationships that are used to estimate effort as a function of workload are called “Effort Estimating Relationships” (EER’s), analogous to “Cost Estimating Relationships” (CER’s).

The approach includes two distinct steps. In the first step, the CET develops a set of regression equations based on the information on existing data activities included in the CDB, and in the second step, it uses those equations in the course of a process for producing a set of effort estimates for a new data activity.

The CET software package includes the CET, CDB, Users’ Guide, and Technical Description Document. The current version is CET 2.1.

Functional Goals

  • Improve CER for non-staff parameters
  • Improve CDB data collection
  • Improve outlier tests in CET
  • Improve flow and navigation in CET

Evolvability Goals

  • Adapt / extend CET and CDB database to meet changing needs of NASA science and applications program, based on guidance / feedback from NASA program managers.
  • Host CET on Web server
  • Continue annual release schedule

Usability Goals

  • Based on feedback from users, improve ease of learning and use, improve user satisfaction.
  • Improve efficiency, maintainability, error performance.

Software Packages

This software is released under the terms and conditions of the NASA Open Source Agreement (NOSA) Version 1.1 or later.
Cost Estimation Toolkit NOSA


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  • Page Last Updated: February 27, 2015
  • Page Editor: Adil Anis
  • NASA Official: Enidia Santiago-Arce