Keith Warfield - Academia.edu (original) (raw)

Uploads

Papers by Keith Warfield

Research paper thumbnail of The Exo-S probe class starshade mission

Techniques and Instrumentation for Detection of Exoplanets VII, 2015

Research paper thumbnail of Cost Model Validation: A Technical and Cultural Approach

This paper summarizes how JPL's Parametric Mission Cost Model (PMCM) has been validated using... more This paper summarizes how JPL's Parametric Mission Cost Model (PMCM) has been validated using bo@ foqnal statistical methods and a variety of peer and management reviews in order to establish organizational acceptance of the cost model estimates. The need for statistical and also organizational validation is heightened when providing cost models and cost estimates in a concurrent engineering environment typical of the advanced design teams that exist at JPL 8s well as at other aerospace organizations, e.g. Aerospace Corporation and Goddard Space Flight Center. Topics discussed include 1. Statistical Validation Approach and Results 2. Organizational Vaiidation (review) process and how it developed support and consensus 3. Discussion of how validation drove the shape and content of the model. for the model at an engineering and project management level

Research paper thumbnail of Spreadsheets in Team X: Preserving Order in an Inherently Chaotic Environment

JPL is NASA's prime center for deep space missions. In response to the need to reduce the cos... more JPL is NASA's prime center for deep space missions. In response to the need to reduce the cost and time to complete early concept studies and proposals JPL created the first concurrent engineering team in the aerospace industry: Team X. Started in 1995, Team X has carried out over 800 studies, dramatically reducing the time and cost involved, and has been the model for other concurrent engineering teams both within NASA and throughout the larger aerospace community. Since its inception, the software backbone of this highly successful design team - engaged in examining some of NASA's cutting edge concepts - has been the unassuming spreadsheet. Over the years the Team X spreadsheet-based tools have evolved from simple standalone engineering models into a networked spreadsheet intensive system with real time parameter updating. Recent new capabilities include stochastic cost estimation and a graphical drag and drop block diagram that automatically populates the related spreadsh...

Research paper thumbnail of Aerospace Concurrent Engineering Design Teams: Current State, Next Steps and a Vision for the Future

AIAA SPACE 2011 Conference & Exposition, 2011

Research paper thumbnail of Characterizing Distributed Concurrent Engineering Teams: A Descriptive Framework for Aerospace Concurrent Engineering Design Teams

AIAA SPACE 2011 Conference & Exposition, 2011

Research paper thumbnail of 3 Parametric Cost Modeling of Space Missions Using the Develop New Projects (DNP) Implementation Process

INCOSE International Symposium, 1999

This paper presents an overview of a parametric cost model that has been built at JPL to estimate... more This paper presents an overview of a parametric cost model that has been built at JPL to estimate costs of future, deep space, robotic science missions. Due to the recent dramatic changes in JPL business practices brought about by an internal reengineering effort known as develop new products (DNF'), high-level historic cost data is no longer considered analogous to future missions. Therefore, the historic data is of little value in forecasting costs for projects developed using the DNP process. This has lead to the development of an approach for obtaining expert opinion and also for combining actual data with expert opinion to provide a cost database for future missions. In addition, the DNP cost model has a maximum of objective cost drivers which reduces the likelihood of model input error. Version 2 is now under development which expands the model capabilities, links it more tightly with key design technical parameters, and is grounded in more rigorous statistical techniques. The challenges faced in building this model will be discussed, as well as it's background, development approach, status, validation, and future plans.

Research paper thumbnail of Exo-C: a probe-scale space observatory for direct imaging and spectroscopy of extrasolar planetary systems

Techniques and Instrumentation for Detection of Exoplanets VII, 2015

Research paper thumbnail of The Exo-S probe class starshade mission

Techniques and Instrumentation for Detection of Exoplanets VII, 2015

Research paper thumbnail of Cost Model Validation: A Technical and Cultural Approach

This paper summarizes how JPL's Parametric Mission Cost Model (PMCM) has been validated using... more This paper summarizes how JPL's Parametric Mission Cost Model (PMCM) has been validated using bo@ foqnal statistical methods and a variety of peer and management reviews in order to establish organizational acceptance of the cost model estimates. The need for statistical and also organizational validation is heightened when providing cost models and cost estimates in a concurrent engineering environment typical of the advanced design teams that exist at JPL 8s well as at other aerospace organizations, e.g. Aerospace Corporation and Goddard Space Flight Center. Topics discussed include 1. Statistical Validation Approach and Results 2. Organizational Vaiidation (review) process and how it developed support and consensus 3. Discussion of how validation drove the shape and content of the model. for the model at an engineering and project management level

Research paper thumbnail of Spreadsheets in Team X: Preserving Order in an Inherently Chaotic Environment

JPL is NASA's prime center for deep space missions. In response to the need to reduce the cos... more JPL is NASA's prime center for deep space missions. In response to the need to reduce the cost and time to complete early concept studies and proposals JPL created the first concurrent engineering team in the aerospace industry: Team X. Started in 1995, Team X has carried out over 800 studies, dramatically reducing the time and cost involved, and has been the model for other concurrent engineering teams both within NASA and throughout the larger aerospace community. Since its inception, the software backbone of this highly successful design team - engaged in examining some of NASA's cutting edge concepts - has been the unassuming spreadsheet. Over the years the Team X spreadsheet-based tools have evolved from simple standalone engineering models into a networked spreadsheet intensive system with real time parameter updating. Recent new capabilities include stochastic cost estimation and a graphical drag and drop block diagram that automatically populates the related spreadsh...

Research paper thumbnail of Aerospace Concurrent Engineering Design Teams: Current State, Next Steps and a Vision for the Future

AIAA SPACE 2011 Conference & Exposition, 2011

Research paper thumbnail of Characterizing Distributed Concurrent Engineering Teams: A Descriptive Framework for Aerospace Concurrent Engineering Design Teams

AIAA SPACE 2011 Conference & Exposition, 2011

Research paper thumbnail of 3 Parametric Cost Modeling of Space Missions Using the Develop New Projects (DNP) Implementation Process

INCOSE International Symposium, 1999

This paper presents an overview of a parametric cost model that has been built at JPL to estimate... more This paper presents an overview of a parametric cost model that has been built at JPL to estimate costs of future, deep space, robotic science missions. Due to the recent dramatic changes in JPL business practices brought about by an internal reengineering effort known as develop new products (DNF'), high-level historic cost data is no longer considered analogous to future missions. Therefore, the historic data is of little value in forecasting costs for projects developed using the DNP process. This has lead to the development of an approach for obtaining expert opinion and also for combining actual data with expert opinion to provide a cost database for future missions. In addition, the DNP cost model has a maximum of objective cost drivers which reduces the likelihood of model input error. Version 2 is now under development which expands the model capabilities, links it more tightly with key design technical parameters, and is grounded in more rigorous statistical techniques. The challenges faced in building this model will be discussed, as well as it's background, development approach, status, validation, and future plans.

Research paper thumbnail of Exo-C: a probe-scale space observatory for direct imaging and spectroscopy of extrasolar planetary systems

Techniques and Instrumentation for Detection of Exoplanets VII, 2015

Log In