SAWE SAWE Store https://www.sawe.org Society of Allied Weight Engineers, Inc. Fri, 29 May 2026 19:58:21 +0000 en-US hourly 1 https://wordpress.org/?v=7.0 231197347 3844 Unintentional Lateral Imbalance Calculation Methodology for Freighter Aircrafts https://www.sawe.org/product/3844-unintentional-lateral-imbalance-calculation-methodology-for-freighter-aircrafts/ Fri, 29 May 2026 17:16:02 +0000 https://www.sawe.org/?post_type=product&p=11476 Paper
Alejandro Fiestras Corcho: 3844. Unintentional Lateral Imbalance Calculation Methodology for Freighter Aircrafts

Abstract

In heavy-cargo operations, lateral imbalance is a silent threat to flight efficiency. This methodology introduces a proactive simulation framework designed to identify and prevent "non-viable" loading states before the process even begins. It specifically targets the complexity of empty positions, leading to scenarios where asymmetrical cargo locking or mechanical failures prevent balanced loading across the aircraft’s roll axis. The method, based on a published patent (ref [1]), allows the user to explore specific cargo layouts with stochastic weight distributions. The system executes multiple simulations to project the accumulated lateral moment. This allows the method to assess flight feasibility against given limit conditions, even when exact individual weights are unknown a priori. Key Technical Advantages:
  • Preventive Risk Mitigation: It establishes a clear "Viable/Non-Viable" binary before any physical loading occurs, preventing potentially inconvenient roll-axis moments.
  • Stochastic Modeling: Uses input probability functions to account for weight uncertainty, ensuring efficiency in real-world conditions where load data is often uncertain.
  • Asymmetrical Failure Analysis: Specifically models the impact of "locked" or disabled cargo locations, turning a complex mechanical limitation into a predictable data point.
This method transforms aircraft loading from a manual estimation task into a data-driven protocol, ensuring that no freighter departs with a lateral moment profile that is not convenient for the airline.]]> Paper
Alejandro Fiestras Corcho: 3844. Unintentional Lateral Imbalance Calculation Methodology for Freighter Aircrafts

Abstract

In heavy-cargo operations, lateral imbalance is a silent threat to flight efficiency. This methodology introduces a proactive simulation framework designed to identify and prevent "non-viable" loading states before the process even begins. It specifically targets the complexity of empty positions, leading to scenarios where asymmetrical cargo locking or mechanical failures prevent balanced loading across the aircraft’s roll axis. The method, based on a published patent (ref [1]), allows the user to explore specific cargo layouts with stochastic weight distributions. The system executes multiple simulations to project the accumulated lateral moment. This allows the method to assess flight feasibility against given limit conditions, even when exact individual weights are unknown a priori. Key Technical Advantages:
  • Preventive Risk Mitigation: It establishes a clear "Viable/Non-Viable" binary before any physical loading occurs, preventing potentially inconvenient roll-axis moments.
  • Stochastic Modeling: Uses input probability functions to account for weight uncertainty, ensuring efficiency in real-world conditions where load data is often uncertain.
  • Asymmetrical Failure Analysis: Specifically models the impact of "locked" or disabled cargo locations, turning a complex mechanical limitation into a predictable data point.
This method transforms aircraft loading from a manual estimation task into a data-driven protocol, ensuring that no freighter departs with a lateral moment profile that is not convenient for the airline.]]> 11476 3843 Digital Exposure of Mass Properties Data https://www.sawe.org/product/3843-digital-exposure-of-mass-properties-data/ Fri, 29 May 2026 17:05:19 +0000 https://www.sawe.org/?post_type=product&p=11475 Paper
Nick Thies: 3843. Digital Exposure of Mass Properties Data
 

Abstract

Providing mass properties data for the consumption of others is, and may always be, a deliberate act. Whether that data takes the form of a periodic data deliverable, like a status report, or a specific response to a customer question, Mass Properties Engineers must frequently mine and manipulate data to satisfy the needs of others. The data maintained within any mass properties database has a breadth that far exceeds simple numerical values of weight, center of gravity, and inertia. Most often, a database includes a labyrinth of codes and descriptors necessary to sort, parse, and aggregate those core numerical values in a meaningful way. Few people other than the Mass Properties Engineers tasked with maintaining that data have any real success gathering/assessing the data sufficiently well to satisfy specific data requests. As a result, both Mass Properties Engineers and customers persist in a request/provide, request/provide paradigm. Even when considering periodic data deliverables, this cycle is preserved (with an implied request). Establishing methods by which mass properties data can be openly exposed, in a meaningful way, serves to break down this cycle. Many data requests need not be asked again; the data is always available without request. In some cases, periodic data deliverables are challenged, relegated to historical practices, as they are replaced by real-time or near-real-time data. However, realizing such a paradigm-breaking scenario cannot occur without one thing – a deliberate act to do so. This paper presents fundamental changes which enable digital exposure of mass properties data.]]> Paper
Nick Thies: 3843. Digital Exposure of Mass Properties Data
 

Abstract

Providing mass properties data for the consumption of others is, and may always be, a deliberate act. Whether that data takes the form of a periodic data deliverable, like a status report, or a specific response to a customer question, Mass Properties Engineers must frequently mine and manipulate data to satisfy the needs of others. The data maintained within any mass properties database has a breadth that far exceeds simple numerical values of weight, center of gravity, and inertia. Most often, a database includes a labyrinth of codes and descriptors necessary to sort, parse, and aggregate those core numerical values in a meaningful way. Few people other than the Mass Properties Engineers tasked with maintaining that data have any real success gathering/assessing the data sufficiently well to satisfy specific data requests. As a result, both Mass Properties Engineers and customers persist in a request/provide, request/provide paradigm. Even when considering periodic data deliverables, this cycle is preserved (with an implied request). Establishing methods by which mass properties data can be openly exposed, in a meaningful way, serves to break down this cycle. Many data requests need not be asked again; the data is always available without request. In some cases, periodic data deliverables are challenged, relegated to historical practices, as they are replaced by real-time or near-real-time data. However, realizing such a paradigm-breaking scenario cannot occur without one thing – a deliberate act to do so. This paper presents fundamental changes which enable digital exposure of mass properties data.]]> 11475 3842 Modernizing SumMassProps https://www.sawe.org/product/3842-modernizing-summassprops/ Fri, 29 May 2026 16:36:45 +0000 https://www.sawe.org/?post_type=product&p=11473 Paper
Robert Zimmerman: 3842. Modernizing SumMassProps
 

Abstract

In 2003 I created the initial version of SumMassProps, an Excel Add-In that created a macro-based Excel solution for correctly summing the 10 basic mass properties (Mass, 3-axis Centers of Gravity, 3-axis Moments of Inertia, and 3-axis Products of Inertia). This was released as SAWE Paper 3310. This solution had a bare-bones Graphical User Interface (GUI) that only created the necessary header lines required to run the Add-In, all the “guts” of the solution were accessed using Excel’s built-in Paste Function) to access each of the Add-In’s summing functions. This was not ideal. Although the original 2003 version of SumMassProps did ensure that the consistent equations were used to sum mass properties, in 2012 a major update was issued as SAWE paper 3574. This update included a full GUI utilizing menus to access the various functions, as well as adding additional functionality to the Add-In. This version also included corrections to the summing of mass properties uncertainties as covered in SAWE paper 3360 “Are You Sure?”. In 2009 Microsoft created a different way to access functions and macros, calling this new method the Ribbon. Later, access to functions and macros using menus was discontinued within Visual Basic for Applications, the language used to create the SumMassProps Add-In, and the Add-In would fail to load. This forced either a return to the 2003 method or a re-write of the program to encompass the new Ribbon paradigm versus a menu driven paradigm. This paper describes the necessary steps to implement a Ribbon-based Add-In, and will also be a release for SumMassProps Version 10 (2026) that utilizes a Ribbon-based paradigm, which necessitates a re-write of the Tutorial and the User Guide to walk the user through the Add-In.]]> Paper
Robert Zimmerman: 3842. Modernizing SumMassProps
 

Abstract

In 2003 I created the initial version of SumMassProps, an Excel Add-In that created a macro-based Excel solution for correctly summing the 10 basic mass properties (Mass, 3-axis Centers of Gravity, 3-axis Moments of Inertia, and 3-axis Products of Inertia). This was released as SAWE Paper 3310. This solution had a bare-bones Graphical User Interface (GUI) that only created the necessary header lines required to run the Add-In, all the “guts” of the solution were accessed using Excel’s built-in Paste Function) to access each of the Add-In’s summing functions. This was not ideal. Although the original 2003 version of SumMassProps did ensure that the consistent equations were used to sum mass properties, in 2012 a major update was issued as SAWE paper 3574. This update included a full GUI utilizing menus to access the various functions, as well as adding additional functionality to the Add-In. This version also included corrections to the summing of mass properties uncertainties as covered in SAWE paper 3360 “Are You Sure?”. In 2009 Microsoft created a different way to access functions and macros, calling this new method the Ribbon. Later, access to functions and macros using menus was discontinued within Visual Basic for Applications, the language used to create the SumMassProps Add-In, and the Add-In would fail to load. This forced either a return to the 2003 method or a re-write of the program to encompass the new Ribbon paradigm versus a menu driven paradigm. This paper describes the necessary steps to implement a Ribbon-based Add-In, and will also be a release for SumMassProps Version 10 (2026) that utilizes a Ribbon-based paradigm, which necessitates a re-write of the Tutorial and the User Guide to walk the user through the Add-In.]]> 11473 3856 Weight Management of Ground Vehicles: A Mass Properties Control Framework for Road, Off-Road, and Special-Purpose Platforms https://www.sawe.org/product/3856-weight-management-of-ground-vehicles-a-mass-properties-control-framework-for-road-off-road-and-special-purpose-platforms/ Fri, 29 May 2026 16:35:21 +0000 https://www.sawe.org/?post_type=product&p=11472 Paper
Hans-Peter Dahm: 3856. Weight Management of Ground Vehicles: A Mass Properties Control Framework for Road, Off-Road, and Special-Purpose Platforms
 

Abstract

Ground vehicles are frequently managed by curb mass, gross vehicle mass, or payload, but those scalar measures do not adequately control the engineering risk created by the distribution and maturity of mass. This paper presents a practical mass properties engineering framework for weight management of ground vehicles, including passenger cars, trucks, buses, motorcycles, electric bicycles, construction machines, special-purpose vehicles, and tracked platforms. The objective is to convert weight management from late-stage reporting into a closed-loop control process that supports architecture decisions, homologation, stability, braking, steering, energy use, payload, and lifecycle configuration control. The proposed approach combines top-down allocation of mass, center of gravity, axle loads, wheel loads, inertias, and reserves with bottom-up roll-ups from computer-aided design, bills of material, supplier data, and physical measurement. It distinguishes current mass from forecast mass, mass growth allowance from uncertainty, and certification limits from engineering margins. The method uses a defined mass state, a vehicle-family-specific risk register, a gate-based verification plan, and an escalation path whenever not-to-exceed values, axle reactions, center-of-gravity limits, or stability constraints are threatened. The central finding is that the best ground-vehicle program is not necessarily the lightest program; it is the program whose mass properties are controlled at the right level of maturity for each decision. For passenger cars and performance vehicles, the dominant risks are variant accretion, battery placement, unsprung mass, and inertia drift. For trucks and buses, payload, axle-load reserve, bodybuilder integration, roof-mounted systems, and rollover sensitivity dominate. For two-wheel vehicles, rider, battery, and luggage locations must be treated as part of the system. For construction and tracked vehicles, implement position, ballast, soil pressure, and transport configuration require explicit mass states. The paper concludes with an implementation checklist, for example status record, and peer-review checklist intended for adaptation to specific ground-vehicle programs. Keywords: mass properties engineering; weight management; ground vehicles; center of gravity; axle loads; moments of inertia; mass growth; uncertainty; vehicle development; verification.]]> Paper
Hans-Peter Dahm: 3856. Weight Management of Ground Vehicles: A Mass Properties Control Framework for Road, Off-Road, and Special-Purpose Platforms
 

Abstract

Ground vehicles are frequently managed by curb mass, gross vehicle mass, or payload, but those scalar measures do not adequately control the engineering risk created by the distribution and maturity of mass. This paper presents a practical mass properties engineering framework for weight management of ground vehicles, including passenger cars, trucks, buses, motorcycles, electric bicycles, construction machines, special-purpose vehicles, and tracked platforms. The objective is to convert weight management from late-stage reporting into a closed-loop control process that supports architecture decisions, homologation, stability, braking, steering, energy use, payload, and lifecycle configuration control. The proposed approach combines top-down allocation of mass, center of gravity, axle loads, wheel loads, inertias, and reserves with bottom-up roll-ups from computer-aided design, bills of material, supplier data, and physical measurement. It distinguishes current mass from forecast mass, mass growth allowance from uncertainty, and certification limits from engineering margins. The method uses a defined mass state, a vehicle-family-specific risk register, a gate-based verification plan, and an escalation path whenever not-to-exceed values, axle reactions, center-of-gravity limits, or stability constraints are threatened. The central finding is that the best ground-vehicle program is not necessarily the lightest program; it is the program whose mass properties are controlled at the right level of maturity for each decision. For passenger cars and performance vehicles, the dominant risks are variant accretion, battery placement, unsprung mass, and inertia drift. For trucks and buses, payload, axle-load reserve, bodybuilder integration, roof-mounted systems, and rollover sensitivity dominate. For two-wheel vehicles, rider, battery, and luggage locations must be treated as part of the system. For construction and tracked vehicles, implement position, ballast, soil pressure, and transport configuration require explicit mass states. The paper concludes with an implementation checklist, for example status record, and peer-review checklist intended for adaptation to specific ground-vehicle programs. Keywords: mass properties engineering; weight management; ground vehicles; center of gravity; axle loads; moments of inertia; mass growth; uncertainty; vehicle development; verification.]]> 11472 3855 Double-Shell and Sandwich Fuselages for Future Aircraft https://www.sawe.org/product/3855-double-shell-and-sandwich-fuselages-for-future-aircraft/ Fri, 29 May 2026 16:30:32 +0000 https://www.sawe.org/?post_type=product&p=11470 Paper
Hans-Peter Dahm: 3855. Double-Shell and Sandwich Fuselages for Future Aircraft
 

Abstract

There are several fuselage concepts which show alternatives in comparison to the classical cylindrical fuselage concept. Double-shell fuselages include classic double-bubble cabins, double-D variants, and multi-shell arrangements in which one or more near-cylindrical pressure lobes are enclosed by an outer aerodynamic shell. This paper restructures the topic and describes basic structural-mechanical behavior of double-shell sandwich fuselages. The objective is to determine when shell duplication in a sandwich creates a real mass benefit and when it redistributes mass among pressure skins, outer shells, webs, floors, and reinforcement details. A literature review is combined with a mechanics-based preliminary sizing method and a worked A220-like derived sample calculation. The paper then develops a separate aircraft-level estimate for a concentric circular double-shell sandwich concept manufactured as pre-equipped major shell modules. The approach combines a bottom-up structural mass build-up for the circular double-shell fuselage concept with a top-down aircraft-level fuselage-group allocation for the broader savings assessment. These two approaches serve different purposes and therefore produce different mass values. A future aircraft must integrate cryogenic hydrogen tanks, insulation, battery systems, cable runs, thermal management hardware, and larger secondary systems volumes than conventional kerosene aircraft. The architecture-only estimate yields a net installed mass saving of about 1.28 t. When a conservative transition from a public A220-like mixed-material fuselage baseline to a full thermoplastic-resin CFRP fuselage is added, with overlap correction to avoid double counting, the holistic aircraft-level rises to about 2.01 t. On a 39.0 t class level operating-empty-weight baseline this corresponds to about 5.16% of OEW, while remaining a concept-level result rather than a validated OEM design value. Public thermoplastic fuselage demonstrator results are treated conservatively as weight-positive but recurring-cost neutral relative to a metallic barrel, so the recurring production benefit remains dominated by modular preinstallation and reduced detail count at about €0.30 million per aircraft.]]> Paper
Hans-Peter Dahm: 3855. Double-Shell and Sandwich Fuselages for Future Aircraft
 

Abstract

There are several fuselage concepts which show alternatives in comparison to the classical cylindrical fuselage concept. Double-shell fuselages include classic double-bubble cabins, double-D variants, and multi-shell arrangements in which one or more near-cylindrical pressure lobes are enclosed by an outer aerodynamic shell. This paper restructures the topic and describes basic structural-mechanical behavior of double-shell sandwich fuselages. The objective is to determine when shell duplication in a sandwich creates a real mass benefit and when it redistributes mass among pressure skins, outer shells, webs, floors, and reinforcement details. A literature review is combined with a mechanics-based preliminary sizing method and a worked A220-like derived sample calculation. The paper then develops a separate aircraft-level estimate for a concentric circular double-shell sandwich concept manufactured as pre-equipped major shell modules. The approach combines a bottom-up structural mass build-up for the circular double-shell fuselage concept with a top-down aircraft-level fuselage-group allocation for the broader savings assessment. These two approaches serve different purposes and therefore produce different mass values. A future aircraft must integrate cryogenic hydrogen tanks, insulation, battery systems, cable runs, thermal management hardware, and larger secondary systems volumes than conventional kerosene aircraft. The architecture-only estimate yields a net installed mass saving of about 1.28 t. When a conservative transition from a public A220-like mixed-material fuselage baseline to a full thermoplastic-resin CFRP fuselage is added, with overlap correction to avoid double counting, the holistic aircraft-level rises to about 2.01 t. On a 39.0 t class level operating-empty-weight baseline this corresponds to about 5.16% of OEW, while remaining a concept-level result rather than a validated OEM design value. Public thermoplastic fuselage demonstrator results are treated conservatively as weight-positive but recurring-cost neutral relative to a metallic barrel, so the recurring production benefit remains dominated by modular preinstallation and reduced detail count at about €0.30 million per aircraft.]]> 11470 3854 The Impact of Changing Test Weight Vertical Center of Gravity on a Shipboard Inclining Experiment https://www.sawe.org/product/3854-the-impact-of-changing-test-weight-vertical-center-of-gravity-on-a-shipboard-inclining-experiment/ Fri, 29 May 2026 16:26:53 +0000 https://www.sawe.org/?post_type=product&p=11469 Paper
Alan Bryden, Rob Dvorak: 3854. Roll and Horizontal Axis Moment of Inertia (MOI) Measurements using a Gravity Pendulum
 

Abstract

Changes to the vertical position of the test weights during the course of an inclining experiment affects the experiment results. In most cases, weight movements are perpendicular to the ship’s centerline plane and do not change in height. However, this may not be practical, or it may be more economical to raise or lower the elevation of the weights during the inclining experiment. It is up to the naval architect to determine the magnitude of this effect and whether it should be included in the calculations. This paper assists the naval architect in consideration of alternative means of performing an inclining experiment without sacrificing accuracy. This paper takes a geometric approach to the derivation of the GM equation and factors in the adjustment due to vertical weight movements. “Small angle” assumptions for the GM calculation remain and the effect of changes to those assumptions are not addressed in this paper. The primary drivers of error when moving the weights vertically are the magnitude of the angle of inclination and the ratio of the distances of the vertical movement with respect to the horizontal movement. This paper presents a correction factor tool for naval architects to determine the magnitude of the effect and how to include the effect in the results if necessary.]]> Paper
Alan Bryden, Rob Dvorak: 3854. Roll and Horizontal Axis Moment of Inertia (MOI) Measurements using a Gravity Pendulum
 

Abstract

Changes to the vertical position of the test weights during the course of an inclining experiment affects the experiment results. In most cases, weight movements are perpendicular to the ship’s centerline plane and do not change in height. However, this may not be practical, or it may be more economical to raise or lower the elevation of the weights during the inclining experiment. It is up to the naval architect to determine the magnitude of this effect and whether it should be included in the calculations. This paper assists the naval architect in consideration of alternative means of performing an inclining experiment without sacrificing accuracy. This paper takes a geometric approach to the derivation of the GM equation and factors in the adjustment due to vertical weight movements. “Small angle” assumptions for the GM calculation remain and the effect of changes to those assumptions are not addressed in this paper. The primary drivers of error when moving the weights vertically are the magnitude of the angle of inclination and the ratio of the distances of the vertical movement with respect to the horizontal movement. This paper presents a correction factor tool for naval architects to determine the magnitude of the effect and how to include the effect in the results if necessary.]]> 11469 3851 Roll and Horizontal Axis Moment of Inertia (MOI) Measurements using a Gravity Pendulum https://www.sawe.org/product/3851-roll-and-horizontal-axis-moment-of-inertia-moi-measurements-using-a-gravity-pendulum/ Fri, 29 May 2026 16:20:43 +0000 https://www.sawe.org/?post_type=product&p=11468 Paper
James Blair: 3851. Roll and Horizontal Axis Moment of Inertia (MOI) Measurements using a Gravity Pendulum
 

Abstract

Customers with long cylindrical parts have had difficulty measuring the inertia about the roll axis on systems that require the part to be mounted vertical in order to conduct the measurement. This has led to issues with the requirement of a variety of fixtures and risky handling of parts in order to orient the part. Raptor Scientific has developed a measurement system that measures inertia about the roll axis in a horizontal manner using an air bearing fixture and universal rings to measure the time period, and when combined with center of gravity measurements from a KSR instrument and mass measurements, determines the inertia about this axis. This paper examines the goals of the end user, the process used in designing the fixture, final results and accuracy requirements / what is achievable, and lessons learned along the way for the design and build of the final deliverable instrument.]]> Paper
James Blair: 3851. Roll and Horizontal Axis Moment of Inertia (MOI) Measurements using a Gravity Pendulum
 

Abstract

Customers with long cylindrical parts have had difficulty measuring the inertia about the roll axis on systems that require the part to be mounted vertical in order to conduct the measurement. This has led to issues with the requirement of a variety of fixtures and risky handling of parts in order to orient the part. Raptor Scientific has developed a measurement system that measures inertia about the roll axis in a horizontal manner using an air bearing fixture and universal rings to measure the time period, and when combined with center of gravity measurements from a KSR instrument and mass measurements, determines the inertia about this axis. This paper examines the goals of the end user, the process used in designing the fixture, final results and accuracy requirements / what is achievable, and lessons learned along the way for the design and build of the final deliverable instrument.]]> 11468 3846 Vendor Guarantee Weights in Product Development https://www.sawe.org/product/3846-vendor-guarantee-weights-in-product-development/ Fri, 29 May 2026 16:17:18 +0000 https://www.sawe.org/?post_type=product&p=11467 Paper
Doug Fisher: 3846. Vendor Guarantee Weights in Product Development
 

Abstract

Aircraft OEMs outsource significant design and build scope to vendors/suppliers. A Guarantee weight (often termed a Guaranteed-Not-to-Exceed weight) is the maximum allowable delivered weight of a supplier’s item. This paper outlines key considerations for establishing Guarantee weight agreements between design/manufacturing suppliers and aircraft OEMs in the civil aviation industry. Contractually binding Guarantee weights are critical to meeting aircraft performance and safety goals. Because suppliers face penalties for non-compliance, Guarantee weights must be realistically achievable within program cost and schedule constraints. Guarantees are often set early in development, before the design is stable. Early unknowns create weight risk that must be accounted for (via management reserve, weight-growth allowance, or other countermeasures) to reach an agreement acceptable to both parties.]]> Paper
Doug Fisher: 3846. Vendor Guarantee Weights in Product Development
 

Abstract

Aircraft OEMs outsource significant design and build scope to vendors/suppliers. A Guarantee weight (often termed a Guaranteed-Not-to-Exceed weight) is the maximum allowable delivered weight of a supplier’s item. This paper outlines key considerations for establishing Guarantee weight agreements between design/manufacturing suppliers and aircraft OEMs in the civil aviation industry. Contractually binding Guarantee weights are critical to meeting aircraft performance and safety goals. Because suppliers face penalties for non-compliance, Guarantee weights must be realistically achievable within program cost and schedule constraints. Guarantees are often set early in development, before the design is stable. Early unknowns create weight risk that must be accounted for (via management reserve, weight-growth allowance, or other countermeasures) to reach an agreement acceptable to both parties.]]> 11467 3845 The Earned Value Evolution of the Plan to Perform https://www.sawe.org/product/3845-the-earned-value-evolution-of-the-plan-to-perform/ Fri, 29 May 2026 16:04:48 +0000 https://www.sawe.org/?post_type=product&p=11465 Paper
Patrick Brown: 3845. The Earned Value Evolution of the Plan to Perform
 

Abstract

Earned Value Management (EVM) is a widely recognized project management technique for objectively measuring project performance by integrating scope, schedule, and cost. The Mass Properties Plan to Perform (PtP) is used in the total product lifecycle Program Development phase for managing and communicating status empty, target, and not-to-exceed (NTE) weights. This paper explores the possibility of superimposing the EVM techniques onto the PtP process. And by leveraging the EVM vernacular, the author hopes to achieve the following results:
  • PtP with ‘earned weights’ (status and NTE as compared to target weights)
  • Improved Program, Chief Engineer, and Integrated Team communication (performance indices and variance analysis)
  • Wider understanding within non-technical disciplines e.g. Business Management team, Global Supply Chain, etc. (conceptual commonality with established EVM and relationships)
While the concepts presented in the paper are practical, and loosely follow both EVM and PtP methods, the application and examples provided are hypothetical.]]> Paper
Patrick Brown: 3845. The Earned Value Evolution of the Plan to Perform
 

Abstract

Earned Value Management (EVM) is a widely recognized project management technique for objectively measuring project performance by integrating scope, schedule, and cost. The Mass Properties Plan to Perform (PtP) is used in the total product lifecycle Program Development phase for managing and communicating status empty, target, and not-to-exceed (NTE) weights. This paper explores the possibility of superimposing the EVM techniques onto the PtP process. And by leveraging the EVM vernacular, the author hopes to achieve the following results:
  • PtP with ‘earned weights’ (status and NTE as compared to target weights)
  • Improved Program, Chief Engineer, and Integrated Team communication (performance indices and variance analysis)
  • Wider understanding within non-technical disciplines e.g. Business Management team, Global Supply Chain, etc. (conceptual commonality with established EVM and relationships)
While the concepts presented in the paper are practical, and loosely follow both EVM and PtP methods, the application and examples provided are hypothetical.]]> 11465 3841 Recommended Practice (RP) Functional Sub-codes: Simplified Part Categories for Better Early Program Weight Estimation and Enabling AI Analysis https://www.sawe.org/product/3841-recommended-practice-functional-sub-codes-simplified-part-categories-for-better-early-program-weight-estimation-and-enabling-ai-analysis/ Fri, 29 May 2026 16:02:25 +0000 https://www.sawe.org/?post_type=product&p=11464 Paper
Roman Aman: 3841. Recommended Practice (RP) Functional Sub-codes: Simplified Part Categories for Better Early Program Weight Estimation and Enabling AI Analysis
 

Abstract

In today's world Mass Properties engineers are expected to do more with less. This paper walks through a breakthrough method of using simplified part categories (Recommended Practice Sub-codes) to quickly summarize data, check for errors, and generate new parametric relationships. The method, is simple, proven, and perhaps the most game changing addition to Recommended Practice (RP) in decades. As a result of using this method any Mass Properties engineer will be able to formulate important parametric weight estimation relationships for future programs and by using those relationships estimate missing components at a detailed part level. Just as recommended practices use Page, Column, Row, codes to define the function of parts. Within that function there may be dozens of different kinds of parts that leave people unable to recreate details during preliminary design. Likewise, RP functional codes take time and experience to assign at a detailed level and must be re-coded each time the design changes. Sub-codes or part categories are simpler and stay the same no matter what RP function and can be almost entirely coded automatically saving time. They are intended to be used with RP functional codes. The RP coding tells us what system or function a part has as part of the overall vehicle system for example Hydraulics. The sub-codes go one more level lower and define what that part is – tube, fitting, bracket, P-clamp, or fluid. With this data we can estimate parts at a lower level and better estimate missing parts during preliminary design. Finally, due to the automated nature of sub-codes aka part categories, we can fuel future AI efforts by forming thousands of additional weight estimating relationships as compared to RP functional coding alone. The simplicity of these categories makes them far more likely to align one design to another. With simplicity and automation also comes the ability to error check weight estimates faster.]]> Paper
Roman Aman: 3841. Recommended Practice (RP) Functional Sub-codes: Simplified Part Categories for Better Early Program Weight Estimation and Enabling AI Analysis
 

Abstract

In today's world Mass Properties engineers are expected to do more with less. This paper walks through a breakthrough method of using simplified part categories (Recommended Practice Sub-codes) to quickly summarize data, check for errors, and generate new parametric relationships. The method, is simple, proven, and perhaps the most game changing addition to Recommended Practice (RP) in decades. As a result of using this method any Mass Properties engineer will be able to formulate important parametric weight estimation relationships for future programs and by using those relationships estimate missing components at a detailed part level. Just as recommended practices use Page, Column, Row, codes to define the function of parts. Within that function there may be dozens of different kinds of parts that leave people unable to recreate details during preliminary design. Likewise, RP functional codes take time and experience to assign at a detailed level and must be re-coded each time the design changes. Sub-codes or part categories are simpler and stay the same no matter what RP function and can be almost entirely coded automatically saving time. They are intended to be used with RP functional codes. The RP coding tells us what system or function a part has as part of the overall vehicle system for example Hydraulics. The sub-codes go one more level lower and define what that part is – tube, fitting, bracket, P-clamp, or fluid. With this data we can estimate parts at a lower level and better estimate missing parts during preliminary design. Finally, due to the automated nature of sub-codes aka part categories, we can fuel future AI efforts by forming thousands of additional weight estimating relationships as compared to RP functional coding alone. The simplicity of these categories makes them far more likely to align one design to another. With simplicity and automation also comes the ability to error check weight estimates faster.]]> 11464