In the cost conscious railroad industry, with increased mergers and decreased budgets, it is necessary for railroad engineers and purchasing agents to provide justification for every expenditure. When deciding which product to buy, particular attention must be paid to product performance. Product performance can be measured by a product’s life cycle cost which combines the life and cost of the product (both capital and maintenance) into a quantitative economic measure of overall product performance. Very few objective tools are available to railroad personnel which help them make optimum economic decisions concerning material selection. Most tools available are not specific to railroads, are not comprehensive enough, or are so complex that they are rarely used, if at all. Only a few tools have been found to be both easy to use and technologically sophisticated. One such tool is the Railway Tie Association’s SelecTie II developed by ZETA-TECH Associates, Inc. for selecting the optimal crosstie/fastener confration for any given railroad operating environment.

SelecTie was first introduced in 1990 as a spreadsheet model which quickly became the standard for life cycle modeling of alternate crosstie configurations. With over 2500 line items of user changeable data, immediate access to analysis results, and research based life cycle equations, the user was quickly and easily provided with a look at the crosstie’s costs over its active service life. Economic comparison of alternate materials and maintenance practices could be evaluated based on the present value costs of the various scenarios. By providing the user with the present value costs for each material, the differences in costs and subsequent return on investment, the user had the ability to determine which alternative was the best economical choice.

The recently developed SelecTie II (See Figure 1) is an upgrade to SelecTie and reports a comprehensive engineering economics model designed for use on a personal computer running Microsoft Windows 3.1 or higher. This model combines the easy to use Windows operating environment and a sophisticated analytical approach that provides railroad users with a user friendly decision support tool. SelecTie II contains standard features common to Windows that will make most users familiar with the Windows environment comfortable in accessing and changing data in the SelecTie II program. These features include pull down menus, icon based toolbar, common file selection and print dialog windows, on-line help, etc.

Figure 1

The model allows the user to enter track and operating characteristics for a segment of track. For each of two alternative crosstie and fastener configuration, SelecTie II calculates present value costs for a number of maintenance activities including tie replacement, rail replacement, surfacing, etc. For each maintenance activity SelecTie II utilizes a life/maintenance cycle, productivity rate, material cost, equipment cost, and labor cost to determine a present value cost for that maintenance activity. Based on these maintenance activities a total cost is developed, along with a net difference in present value costs and corresponding return on investment.

SelecTie II is a state of the art economic benefit analysis tool that provides the user with an easy to use interface for specifying costs and engineering inputs while retaining the sophisticated analytical approach inherent to the original SelecTie. The return on investment is the primary indicator of economic justification and is always available to the user in order to show the effects of changing any given input parameters.

As can be seen in Figure 1, a session form is contained within the SelecTie II main program window which contains the data for a give session or file. Several of these forms may be opened at one time such that multiple documents can be viewed simultaneously. The session form summarizes the economic benefit analysis and contains a summary of the track inputs as well as a space for user added comments and notes. The user has available at all times, the return on investment as well as a present value cost summary for each maintenance activity and each crosstie/fastener configuration. In addition, a breakdown of costs is presented for each specified maintenance activity which can be changed using the pull down list of maintenance activities.

When the user opens a new SelecTie II session, the input variables are defaulted to values based on industry average data. Railroad specific data can be input for any variable and saved as a railroad specific file to be used later for any analysis scenario.

For a given set of track characteristics and operating criteria, several maintenance activities are defined for which the costs of installation and maintenance are calculated for each tie and fastener configuration. The track characteristics are input through a screen which contains information related to the existing layout and operating requirements of the track segment (See Figure 2). Whenever possible, pull down lists, option buttons, and/or check boxes are provided for ease of input.

Figure 2

In addition to the track characteristics input screen, separate input screens are available for the component life cycles (internal model calculations can be overridden by the user), material characteristics, material costs, labor costs, equipment costs, and productivity rates. The individual input screens allow for more intuitive and comprehensive data editing as compared to the original sequential format of the SelecTie spreadsheet model. As an example of the ease of use of the input screens, the material costs input screen is shown in Figure 3 for the tie replacement maintenance activity. Material cost inputs for each maintenance activity can be defined by selecting the desired maintenance activity from the pull down list at the top of the input screen.

Figure 3

Several upgrades have been included in SelecTie II that make it more useful and easier to use. The first upgrade is an ROI window (See Figure 1) that provides the user with a constant update of the return on investment and can be moved to any location that suits the user. The second upgrade is user’s favorites toolbox (See Figure 1) which allows the user to assign any input text box they wish to the favorites toolbox by clicking and dragging the desired input to the favorites window. This provides the user with quick and easy access to any variable they feel they need to change often.

Another upgrade is SelecTie II’s multiple document interface which allows for several sessions to be opened simultaneously to compare results of different input values. An additional upgrade is the capability for sensitivity analysis which allows the user to compare the effects of changing one variable (curvature, tie cost, etc.) while holding all other variables constant. In this manner break even points can be determined for the variable for which the sensitivity analysis is being performed. A sample sensitivity analysis for degree of curvature is shown in Figure 4.

Figure 4

SelecTie II is an unbiased analytical tool for selecting the optimal crosstie/fastener configuration for a particular stretch of track based on the engineering and operating characteristics of that segment. The model has default cost data and engineering life cycle equations that have been based on several years of research. If the users feel that this default information is not consistent with their experience they have the ability to change any input variable. In this manner a railroad engineer or purchasing agent can determine the optimal crosstie/fastener configuration for a defined segment of track knowing the railroad’s experience and costs.