About The Optimal Retirement Planner

The Optimal Retirement Planner (ORP) was originally built to demonstrate the feasibility of implementing a computationally intensive process on an Internet web site that is directed at the retail market. ORP is built using tools and techniques developed in the field of Operations Research over the last 60 years.

Table 1: ORP Web Site Architecture

The core of ORP is an industrial strength linear programming optimizer (BOSC) originally built by William Orchard_Hays and used mostly in feed blending applications. The optimizer is surrounded by a model management system (MathPro), and it's relational database, that describes the model, builds the LP matrix and processes the solution results. MathPro is used mostly for petro chemical refinery simulations. The outer layer is a Perl implemented Common Gateway Interface (CGI) Script that communicates with the browser based client. This simple, straightforward, elegant architecture has remained in place since 1996 surviving many changes to application side of the model.

Linear Programming

Linear Programming (LP) is applicable when a process can be modeled by a set of linear equations. Normally the set will have more variables than equations and thus have no unique solution. LP's objective function assigns a profit or cost to each variable. George Danzig' elegant Simplex Method efficiently finds a solution to the equation set that maximizes the objective function. While this solution is not unique the Simplex Method quarentees that is no better solution.

A typical ORP model has:

  1. 700 equations,
  2. 900 vaiables,
  3. 0.5% density,
  4. looks at 900 potential solutions.
  5. solves in under 2 seconds


James S. Welch, Jr (Resume) is the principle architect, formulator and implementer of ORP. Significant contributions were also made by:

  • Cindy Mumford - CGI script
  • Rodney Wildermuth - CGI script
  • Nick Welch - input form definition
  • Fred Chen, CPA - consultation on financial and tax matters
  • Cha Kang - Screen design
  • William Orchard-Hays - LP Optimizer
Your comments are welcome: orplanner@gmail.com

© 2008, James S. Welch, Jr