A parametric model is a set of related mathematical equations that incorporates variable parameters. A scenario is defined by selecting a value for each parameter. Software project managers use software parametric models and parametric estimation tools to estimate their projects' duration, staffing and cost.
In the early 1980s refinements to earlier models, such as PRICE S and SLIM, and new models, such as SPQR, Checkpoint, ESTIMACS, SEER-SEM or COCOMO and its commercial implementations PCOC, Costimator, GECOMO, COSTAR and Before You Leap emerged.
The prime advantage of these models is that they are objective, repeatable, calibrated and easy to use, although calibration to previous experience may be a disadvantage when applied to a significantly different project.
These models were highly effective for waterfall model, version 1 software projects of the 1980s and highlighted the early achievements of parametrics. As systems became more complex and new languages emerged, different software parametric models emerged that employed new cost estimating relationships, risk analyzers, software sizing, nonlinear software reuse, and personnel continuity.
Nonparametric statistics is a type of statistical analysis that makes minimal assumptions about the underlying distribution of the data being studied. Often these models are infinite-dimensional, rather than finite dimensional, as is parametric statistics. Nonparametric statistics can be used for descriptive statistics or statistical inference. Nonparametric tests are often used when the assumptions of parametric tests are evidently violated.
Creo Parametric, formerly known, together with Creo Elements/Pro, as Pro/Engineer and Wildfire, is a solid modeling or CAD, CAM, CAE, and associative 3D modeling application, running on Microsoft Windows.
The Constructive Cost Model (COCOMO) is a procedural software cost estimation model developed by Barry W. Boehm. The model parameters are derived from fitting a regression formula using data from historical projects.
In industry, product lifecycle management (PLM) is the process of managing the entire lifecycle of a product from its inception through the engineering, design and manufacture, as well as the service and disposal of manufactured products. PLM integrates people, data, processes, and business systems and provides a product information backbone for companies and their extended enterprises.
Design for Six Sigma (DFSS) is a collection of best-practices for the development of new products and processes. It is sometimes deployed as an engineering design process or business process management method. DFSS originated at General Electric to build on the success they had with traditional Six Sigma; but instead of process improvement, DFSS was made to target new product development. It is used in many industries, like finance, marketing, basic engineering, process industries, waste management, and electronics. It is based on the use of statistical tools like linear regression and enables empirical research similar to that performed in other fields, such as social science. While the tools and order used in Six Sigma require a process to be in place and functioning, DFSS has the objective of determining the needs of customers and the business, and driving those needs into the product solution so created. It is used for product or process design in contrast with process improvement. Measurement is the most important part of most Six Sigma or DFSS tools, but whereas in Six Sigma measurements are made from an existing process, DFSS focuses on gaining a deep insight into customer needs and using these to inform every design decision and trade-off.
Cost estimation models are mathematical algorithms or parametric equations used to estimate the costs of a product or project. The results of the models are typically necessary to obtain approval to proceed, and are factored into business plans, budgets, and other financial planning and tracking mechanisms.
Cost estimation in software engineering is typically concerned with the financial spend on the effort to develop and test the software, this can also include requirements review, maintenance, training, managing and buying extra equipment, servers and software. Many methods have been developed for estimating software costs for a given project.
Query optimization is a feature of many relational database management systems and other databases such as NoSQL and graph databases. The query optimizer attempts to determine the most efficient way to execute a given query by considering the possible query plans.
SEER for Software (SEER-SEM) is a project management application used to estimate resources required for software development.
Autodesk Revit is a building information modelling software for architects, structural engineers, mechanical, electrical, and plumbing (MEP) engineers, design for contractors. The original software was developed by Charles River Software, founded in 1997, renamed Revit Technology Corporation in 2000, and acquired by Autodesk in 2002. The software allows users to design a building and structure and its components in 3D, annotate the model with 2D drafting elements, and access building information from the building model's database. Revit is 4D building information modeling application capable with tools to plan and track various stages in the building's lifecycle, from concept to construction and later maintenance and/or demolition.
The Putnam model is an empirical software effort estimation model. The original paper by Lawrence H. Putnam published in 1978 is seen as pioneering work in the field of software process modelling. As a group, empirical models work by collecting software project data and fitting a curve to the data. Future effort estimates are made by providing size and calculating the associated effort using the equation which fit the original data.
In software development, effort estimation is the process of predicting the most realistic amount of effort required to develop or maintain software based on incomplete, uncertain and noisy input. Effort estimates may be used as input to project plans, iteration plans, budgets, investment analyses, pricing processes and bidding rounds.
The project management triangle is a model of the constraints of project management. While its origins are unclear, it has been used since at least the 1950s. It contends that:
The quality of work is constrained by the project's budget, deadlines and scope (features).
The project manager can trade between constraints.
Changes in one constraint necessitate changes in others to compensate or quality will suffer.
Daniel D. Galorath is an American software developer, businessman and author. Galorath is the President and CEO of Galorath Incorporated and one of the chief developers of the project management software known as SEER-SEM.
PRICE Systems was founded in 1975 as a business within the RCA Corporation. It is generally acknowledged as the earliest developer of parametric cost estimation software.
MEDUSA, is a CAD program used in the areas of mechanical and plant engineering by manufacturers and Engineering, Procurement and Construction (EPC) companies. The system's history is closely tied to the beginnings of mainstream CAD and the research culture fostered by Cambridge University and the UK government as well as the resulting transformation of Cambridge into a world-class tech centre in the 1980s.
Parametric design is a design method in which features, such as building elements and engineering components, are shaped based on algorithmic processes rather than direct manipulation. In this approach, parameters and rules establish the relationship between design intent and design response. The term parametric refers to the input parameters that are fed into the algorithms.
Parametric thinking is the influence of engaging in a thinking process that links, relates and outputs calculated actions to generate solutions to problems, rather than simply seeking them. It has its origins in the design fields of urban design, architectural design, interior design, industrial and furniture design. The process is associated with parametricism, a style within contemporary avant-garde architecture, promoted as a successor to post-modern architecture and modern architecture.
Sensitivity analysis identifies how uncertainties in input parameters affect important measures of building performance, such as cost, indoor thermal comfort, or CO2 emissions. Input parameters for buildings fall into roughly three categories:
OpenVSP, also known as Open Vehicle Sketch Pad, is an open source parametric aircraft geometry tool originally developed by NASA. It can be used to create 3D models of aircraft and to support engineering analysis of those models. Predecessors to OpenVSP including VSP and Rapid Aircraft Modeler (RAM) were developed by J.R. Gloudemans and others for NASA beginning in the early 1990s. OpenVSP v2.0 was released as open source under the NOSA license in January 2012. Development has been led by Rob McDonald since around 2012 and has been supported by NASA and AFRL among other contributions.
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