The library BPSIM

The simulation library BPSIM provides a number of C++ classes to enable the programming and simulation of process models designed and/or modelled with Logistics Based Business Modelling. The concepts operation, external agent, transport, waitqueue, choice, archive, means and employee all have their counterpart in BPSIM-classes. The library consists of the following classes:

• data , the class data represents the product or case, i.e. the information, that flows through the process. Note that Logistics Based Business Modelling contains no symbol for data as it only depicts the objects that handle the information;
• datahandler , this abstract class is the basis for all classes that handle information. The following classes are derived from it: operation, transport, waitqueue, choice, archive, and external agent;
• operation , the class operation, derived from datahandler, represents the work done on the data. Operations take time, and are executed by employee's. Sometimes operations result in more than one outgoing dataflow, for instance when an operation issues a request for additional information from a different department;
• agent, the class agent   represents external agents, for instance clients or other organizations or other departments. An agent can either generate data according to some random number distribution, or take data, process it and pass it on to the next datahandler. In the latter case the agent functions as a black box : we only care how long the processing takes, not how it is exactly performed. The class agent is derived from datahandler and the SIM class event;
• transport, this class, derived from datahandler, represents the flow of data from one datahandler to another and the time it takes to transport the data from one datahandler to the next one;
• waitqueue , the class waitqueue is derived from the SIM-classes event and queue and from the class datahandler. A waitqueue functions as a regular queue if it has one incoming dataflow, i.e. transport. When there are more incoming flows, it functions as a waitqueue. Data from one flow is not passed on to the next datahandler until the data from the other flow has arrived. This happens for instance when work on a case cannot continue until additional information has arrived;
• choice , a choice is a datahandler that passes data on to one from two possible datahandlers, based on some condition;
• archive , the class archive models the storage of information;
• means , this class can be used to model resources that are necessary to perform certain operations;
• employee , the class employee models the different people that perform the operations.

As one can see, the objects task and organization unit from LBBM  have no specific counterpart in BPSIM. The reason for this is that having no other datahandler between two operations already implies those operations belong to the same task. Consequently they are executed with no time in between and by the same employee. Also, the fact that tasks are executed in different organization units  does not add any information that changes the behaviour of the simulation. If it takes time to transport information between different units, then that time can be represented by the object of class transport between those units.

For the gathering and analyzing of results the SIM classes histogram  and analysis  are used. The class agent, for example, can be given a histogram to track the lead time of data it has generated. After the simulation has finished the results are printed to standard output.