Models

This page contains links to Excel spreadsheets that are available for browsing or download. These files require Microsoft Excel to run correctly. (The presentations are within the discussion forums.)

Click on the appropriate link under the file’s description to open or save the file. (Please note you must have pop-ups allowed or press crtl when clicking on the download link.) All file sizes are approximate.

To run the Excel spreadsheets you will have to make the following changes (instructions for Excel 2003)

Add the Analysis Toolpak and Analysis Toolpak – VBA
click on the Tools menu
click on add-ins
check the Analysis Toolpak, and Analysis Toolpak – VBA
click OK
 
Set calculations to manual and reiteration to 2
click on tools menu
click on options
click on calculation tab
click on manual
check iteration
set maximum iterations to 2
click OK
 

When the files are run a message may be generated indicating that the files contain macros and asking if they should be run. The macros are required for proper operation. Prior to uploading to this web-site, the files have all been checked using AVG and are virus-free.

The spreadsheets are best viewed at a screen resolution of 1024x 768 pixels or higher. Some of the spreadsheets have had comments added (usually at least to the top left cell) which can be seen by holding the mouse cursor over the little red triangle.

Please note these Excel models are designed to work on English language versions of Excel 2000 to Excel 2007 (although they have been optimised for Excel 2003). The models have not been tested on Excel 2010 version.

Demand analysis

Model showing effect of random variation on waiting lists, including facility to demonstrate effect of holidays, ring-fencing (urgent queue) and waiting list initiatives. It includes a financial module to allow exploration of why variation can cause an inevitable deficit in a service costed by considering averages only.

demand analysis_F.xls

demand analysis_F.zip

Demand analysis 2

Continuous displaying model demonstrating 8 simultaneous queues with random varying demand/capacity. This model can also be used to demonstrate the necessity of having some spare capacity to allow waiting lists to stay under a specified period eg 2 week wait and the benefit of pooling referrals.

demand analysis2.xls

demand analysis2.zip

Flow

Model of flow through a stylised 5-stage process. This model can be used to demonstrate the paradox of trying to minimise “waste” and waiting lists at the same time in attempt to achieve “efficiency”.

patflow.xls

Bed Model Version 4.4

This is a spreadsheet model that demonstrates the impact of variation on bed numbers required to avoid cancellations/diversions. You need to input a profile of admissions and length of stay (please see comments within the spreadsheet….look for little red triangles in the corner of a cell and allow the mouse to hover over the cell). Please remember to follow the Excel set-up instructions (manual calculation and analysis toolpak addin).

bed model4_4.xls

bed model4_4.zip

Guide to using the computer models

This guide takes you through using the standard computer models to understand the basic concepts behind waiting lists and why queues occur.

Guide to the Models 3MB