Continue reading »]]> The Workflow Editor is a part of the net-linx application nxApex. The users of this application are phone directory publishers. Service order is a process to import customer information like address, phone number, placement information, etc and to create and update the existing information in the customer database by creating, deleting or updating this information.

This is a rather complex process and it is different from publisher to publisher. In the past the service order module has been customized for each publisher.

The new workflow editor is used to edit flexible workflows that can be adopted easily by configuration personnel. On the development of this module external student apprentices took part together with experienced internal Java developers.

Workflow Overview

The Workflow Editor is meant for system administrator use only. The information provided in this module is technical and not meant for end user’s view.

The workflow for service order and other DAQ processes is specified in workflow configuration file.
The workflow configuration file contains all workflows. A workflow is always bound to a record type. You can define more than one workflow for a record type. The workflow which should be used must be marked as default.

A workflow can contain the following items: transformation items, validation items, search items and processing items, process flow items, and actions.

All changes made to the record data during the processing of the workflow are discarded after the workflow is finished if not otherwise specified. (See transformation item). Changes made to the administrative data (status, status messages) are saved to the database.

A workflow defines the sequence in which the rules should be processed and the actions depending on the output value of one rule. Rules are for example matching rules.

A workflow consists of a list of workflow items. These workflow items define the rules which should be used and the actions which should be taken on a specific rule output.
If no action is defined for a specific output value is defined, a default action will be used.
The default action for the output values ‘NotUsed’ and ‘Ok’ is ‘Goto Next Item’. The default action for ‘Error’ is ‘Reject Immediate’.
Every action is defined by an action code and a number of parameters.

Continue reading »]]> CrystalWeb is a web reporting application written for a company from Stralsund.

The application is used for hosting Crystal Reports reports in the intranet of the company. The administrator is able to put new reports to the system, which is directly connected to the internal RIOS database for always up tp date data.
This database is also used for the user managment configured by the report administrator. So only authorized users are able to see their appropriate reports.

The application is completely written in C# and ASP.Net 2.0 and is hosted on a Windows 2003 Server.
The Rios database is a MS-SQL server and the report data used by the web application is stored in xml files, which are going to be replaced by a sql server, too (for better performance).

Continue reading »]]> UniCar is a web application for managing car pools.

With UniCar it is possible to manage all aspects of a car pool. Users who need a car from the pool can quickly get the informations about the available cars. Detailed informations about every car are stored, if a user looks for a car for special purposes.

Because the drivers have to fill out a little report after using a car (only about one minute), there are also a lot of analysis possibilities.
A few of this are:

• Who had a specific car at a specific time?
• When was the car refuiled the last time?
• and many more

The pool administrators are also notified for coming service events for the cars (technicals service, security services).
If there are cars that are buyed using leasing contracts, the administrators are also notified about arriving a cars maximum driving distance.
The system also tries to balance the driving distances of the cars. So if a user just wants some car, the system compares the driving distances (under different terms, e.g. purchase contract) and decides which one to reserve. So there is not one car used all the time and another that is standing in the garage for months.

The application is a plugin for the PHProject web application.
Its completely written in PHP and uses MySQL for data.

Continue reading »]]> PathFinder is an application for visualizing path finding algorithms written in by Armin and me.

The source code of pathfinder was published at sourceforge.net (project page).

The application can visualize the whole calculation of the implemented path finding algorithms.
These algorithms are:

• A*
• Depth first
• Breadth first
• Hill climbing
• Beam search
• British museum
• Branch and bound
• Dijkstra
• Depth limited
• Great deluge

Because of a very generic and abstract application design it is very simple to add new algorithms to the repository.

The core data model of PathFinder is a more or less simple graph (nodes connected by edges), that can be overlayed by an image for better visualization (e.g. a map like in the upper picture).
The algorithms try to find a path from a start node to a destination nodes. Depending on the choosen algorithm this path should be the shortest path or just one path. Using the build in graph editor (picture below), the user is able to simply create own graphs.

The most of these algorithms can be heavily parameterized to control the way the algorithm works.
While working, the algorithm notifies the application about each calculation step. So, after the algorithm completes, the user is able to re-run the calculation in every speed or just step by step.
This is great for understandig how a algorithm works or to look for weaknesses in a new algorithm.

After a calculation completes, also some statistics are stored in a history.
Some of these values are:

• Time for calculation
• Steps in the graph model
• Length of the path (and the air distance between start and destination for comparison)
• Count of backtracking nodes (this are nodes visited by the algorithm for calculation but not used in the path)
• The parameters given to the algorithm

Using the history, it is possible to compare differend algorithms or different parameters with each other.
Therefore the pure statistic values can be compared, or the paths can be viewed together on the same graph. So it is very easy to see the differences of algorithms or the impacts of parameters.

The application is written completely in Java (1.6 standard edition) and was part of a projekt at our university.