Economics Network CHEER Virtual Edition

Volume 11, Issue 2, 1997

Software Review: Commander Prism (V3.1)

Martyn Roberts
University of Portsmouth


Commander Prism is the Windows version of Comshare's business modelling tool. It is a development of Comshare's earlier [DOS] modelling tool know as One-Up which itself was a development of a mainframe modelling tool known as System-W (W = Wizard).

Who are Comshare?

Comshare are an international software company based in Ann Arbor, Michigan, USA, and have been in existence over 20 years (a long time in the software world!). They specialise in a particular type of software which has come to be known as decision support systems and have developed a family of products related to this area. Their products are aimed at the corporate rather than private user and they have attracted a particularly loyal following in the UK. Many of the UK's largest companies have adopted Prism which enables Comshare to hold its own annual three day conference where users participate in demonstrations, seminars, discussions, previews etc.

What is a Decision Support System(DSS)?

The term DSS was first used in the early 70s to describe an item of computer software which utilizes data and models to assist managers to solve complex problems. Most organisations today have developed large computerised management information systems (MIS). These systems process day-to-day transactions and from this data provide management with information, usually in the form of printed reports. Usually managers are unable to do anything directly with this information. Analysing the information can be a slow and tedious process requiring numerous manual calculations. A DSS allows managers to take information from a MIS and build complex business models. A DSS does not provide a definitive answer to a particular problem (that would be more the area of an expert system). Instead, by providing a modelling capability it gives managers the ability to explore new and different business scenarios and it provides new insights into business problems.

What is Prism?

Prism is Comshare's version of a DSS. Comshare describe Prism as a multi-dimensional business modelling product. Prism is designed for large, complex, corporate, business applications. It is designed to allow organisations to model a business problem and to analyse the problem from a number of different angles.

The primary interface window is very similar to a conventional spreadsheet, with rows and columns intersecting to form cells. When first attempting to build a model using Prism, it is difficult to see the advantages over a conventional spreadsheet and it may even appear inferior. The observation many students make when first viewing a modelling tool such as Prism is that surely a spreadsheet (eg Quattro, Excel) can do the same for a lot less money! For simple models this is true; but conventional spreadsheets quickly run out power. They are designed for problems which are essentially of a two dimensional nature (occasionally three). However, what if the problem you wish to model has multiple dimensions (Prism can handle up to 9)? Take for instance an example provided by Comshare: Imagine a business wants to model a problems which has:

150 variable items (Units sold, Price, Revenue, Unit Cost etc)
17 time periods per year (12 months, 4 quarterly totals, annual totals)
3 years (2 historical, 1 forecast)
15 groups (offices, consolidated regions)
250 different products
2 data types (actual and budget)

...a model of this problem would contain 57 million individual cells! This is the type of application in which Prism excels and is the reason why many large corporate organisations are willing to pay a substantial amount of money to use Prism.

What Prism is Not

Labelling Prism as a DSS is often taken to infer that it is a tool designed for mathematical and statistical operations. Infact its quantitative capabilities are quite limited and there are much better tools on the market if this is what is required. Its forte is in general business problems which consist of multiple dimensions.

A simple example of a multi-dimensional problem would be that of a motor vehicle manufacturer. It may have thousands of items making up its costs (which may be divided into sub-categories). It may want to track those costs over a number of months. It may also keep a track of sales over a number of months and may want to analyse its sales by:

Although the mathematics in such a problem is not conceptually complex, the structure of the model is very complex and the ability to cope with the different aspects would be difficult for many other modelling tools. Prism allows such a model to be constructed and for the user to switch the dimensions around to view a particular part of the model. The user can then use the model to perform what-if and goal-seek functions.

Data can be fed into the model directly from a management information system(MIS), and infact many organisations use it to sit on top of the traditional MIS and to provide the reporting facility which may otherwise be missing.

Where can Prism be used in teaching?

In the Business School at Portsmouth there are now a number of courses/units in the general area of management science, decision science and business economics at both under-graduate and post-graduate level. Prism is used as an integral part of these courses. At undergraduate the software is used to get students involved in the actual building of models and applying DSS theory. At post-graduate level (where time is a little more limited and students tend to be more interested in the management implications rather than how to design and build) the software is used mainly to demonstrate DSS theory.

An attractive feature of Prism is that it comes complete with an on-line tutorial. This is extremely well written and informative. It is interactive and at the appropriate time asks students to hit certain keys/ click icons etc and then demonstrates the effect of the action. It takes students through all the major aspects of Prism pointing out particular features and how they work. It takes between 2 and 3 hours to complete and is ideal to use if the intention is to simply give students an overview of a DSS without getting into the intricacies of actually building a model.

If you want to go a stage further, and give students exposure to actually building a model, then there is a Getting Started User Guide. This is a step-by-step tutorial which leads the students through a worked example. This takes a further 2 or 3 hours to complete. After this, the students should have the basic skills to commence on a small DSS building project.


Commander Prism is a major improvement over its DOS based predecessor (One-UP). The functionality is basically the same, but the user interface now conforms to the Windows standard. The manner in which the functions are performed is much improved. The online tutorial and getting started guide are useful facilities for getting students familiar with the product and concepts. It is an ideal tool to support courses on business modelling or DSS.


Comshare's Prism publicity literature and manuals.


Comshare Ltd, 22 Chelsea Manner St, London SW3 5RL

Tel: 0171 351 4399
Fax: 0171 351 1251


Negotiated on an individual basis. The software is aimed at the corporate customer rather than the private user. This is reflected in the price which is normally over 1000 per copy! However, a substantial discount is normally given to educational users.

System Requirements (Minimum):

(Comshare's Recommendations):
Microsoft Windows 3.1 (or later).
3Mb Diskspace

(My Recommendations (Min)):
486 Processor

Top | CHEER Home

Copyright 1989-2007