Combing Charts - Introduction

Overview

The Combing Chart is an analysis tool that lets the timetabler carry out a feasibility check on the proposed staff assignments to classes in a single subject, or a number of subjects in the case of an entire department. It is currently normal procedure for Heads of Department to produce a simplistic version of a Combing Chart in the form of a spreadsheet.

Large departments tend to teach in blocks of half or a full year and teams of teachers are assigned to classes within each block. If the same teacher is assigned to two or more blocks, then these blocks cannot be scheduled simultaneously.

Departments that only just comb are considered inflexible, and may need to be scheduled before other departments. In a perfect situation, each large department would comb without exceeding the average loading of the staff. For example, where you have a cycle of 25 teaching periods, it would be ideal if each department combed into no more than 21 periods. If combing reaches 24 or 25 teaching periods this is not ideal and combing that exceeds the 25 teaching periods makes scheduling the timetable an impossible task.

By using the Combing Chart to simulate a number of different scheduling scenarios, you can clearly see where potential problems will occur before you spend a great deal of time actually trying to schedule the timetable.

In use

Select Tools | Combing Chart to display the Select Subjects dialogue.

All the subjects that have been used in the current Model are available for selection. Click the Clear All button to make an individual subject selection. If you want to try to analyse the proposed timetable structure using all available subjects, click the Select All button.

Alternatively, click the Department button to display the Select Department dialogue, then highlight the Description of the Department that you want to work with in the Combing Chart.

Click the OK button to continue, and the Combing Chart is displayed.

A Tour around the Combing Chart Page

The items to be fitted into the Combing Chart are shown in the list on the right-hand side of the page. Each item relates to a block within the block's build matrix. The bands, the block name and its attributes, i.e. the Staff and Rooms, for each item are also displayed in this list. The items are grouped by block and each block is colour coded so that it can be easily distinguished from others.

Every item is allocated a unique short code that is made up of the Year, the band or block identifier and a number, e.g. 10A:1, 7xy:13.

There are a number of ways that the items can be placed into the Combing Chart:

· Click and drag and individual item onto the Combing Chart.

· Hold down the Ctrl key and then click and drag multiple items from a block onto the Combing Chart.

· Click the Insert button to place all the items in the list onto the Combing Chart automatically.

When dragging items onto the Combing Chart, there are a number of things to be aware of:

· The possible destination cells in the Combing Chart ate shown with a black border.

· Items that would be displaced if the dragged items were dropped into their cells are shown with a black background.

· While the drag action is in process, the text inside the cells of any potentially displaced items displays the reason for the displacement, e.g. Band or a list of the conflicting attributes.

· If the drag cursor moves close to the edge of the chart area, the chart scrolls automatically.

Refer to the Nova-T6 handbook, or the eLIM Helpline, for detailed information relating to the functions available in the Combing Chart page.

If you click the Insert button to begin trying to fit the items into the grid, various items may be moved or 'shuffled' around the grid to enable the 'best fit'. Whilst this process is underway, a yellow progress bar is displayed at the bottom of the Combing Chart page detailing the item that is currently being 'fitted'.

Click the Abort button to stop the process at any time before it is complete.

When the shuffling is complete, the items in the grid are coloured in accordance with the block colours in the Model screen. Move the cursor over an item in the grid to view a tool tip displaying the names of the classes and the full list of attributes for the item.

If you want to keep the results of your Combing Chart analysis, click the Copy Chart button to display the Copy to Clipboard/Disk File dialog.

Simon Wood
eLIM, June 2013