the following is a short outline on the basic concepts of a workflow management system based on ibm &# 39 ; s wfms flowmark product : from an enterprise point of view the management of business processes is becoming increasingly important . business processes control what work items are performed by whom and what resources are exploited for this work . in other words , a business process describes how an enterprise will achieve its business goals . a wfms may support both the modeling of business processes and their execution . modeling of a business process as a syntactical unit in a way that is directly supported by a software system is extremely desirable . the software system can also work as an interpreter getting as input such a model . the model , called a process model or workflow model , can then be instantiated and the individual sequence of work steps depending on the context of the instantiation of the model can be determined . such a model of a business process can be perceived as a template for a class of similar processes performed within an enterprise ; it is a schema describing all possible execution variants of a particular kind of business process . an instance of such a model and its interpretation represents an individual process , i . e . a concrete , context dependent execution of a variant prescribed by the model . a wfmss facilitates the management of business processes . it provides a means to describe models of business processes at buildtime and it drives business processes based on an associated model at runtime . the meta model of ibm &# 39 ; s wfms flowmark , i . e . the syntactical elements provided for describing business process models , and the meaning and interpretation of these syntactical elements , is described next . a process model is a complete representation of a process , comprising a process diagram and the settings that define the logic behind the components of the diagram . using various services provided by flowmark these buildtime definitions of the process models are then converted into process templates for use by flowmark at runtime . important components of a flowmark process model are : a process , modeled within flowmark , is a sequence of activities that must be completed to accomplish a task . the process is the top - level element of a flowmark workflow model . in a flowmark process , it can be defined how work is to progress from one activity to the next , which persons are to perform activities and what programs they are to use , and whether any other processes , called subprocesses , are nested in the main process . multiple instances of a flowmark process can run in parallel . activities are the fundamental elements of the meta model . an activity represents a business action that is from a certain perspective a semantical entity of its own . with the model of the business process , an activity might have a fine - structure that is represented in turn via a model , or the details of it are not of interest from a business process modeling point of view . refinement of activities via process models allows for both modeling business processes bottom - up and top - down . an activities is a step within a process ; it represents a piece of work that the assigned person can complete by starting a program or another process . in a process model , the following information is associated with each activity : whether the activity must be started manually by a user or can start automatically . whether control can exit from the activity automatically or the activity must first be confirmed as complete by a user . what data is required as input to the activity and as output from it . program activity : has a program been assigned to perform it . the program is invoked when the activity is started . in a fully automated workflow , the program performs the activity without human intervention . otherwise , the user must start the activity by selecting it from a runtime work list . output from the program can be used in the exit condition for the program activity and for the transition conditions to other activities . process activity : has a ( sub -) process been assigned to perform it . the process is invoked when the activity is started . a process activity represents a way to reuse a set of activities that are common to different processes . output from the process can be used in the exit condition for the process activity and for the transition conditions to other activities . control flow of a running process determines the sequence in which activities are executed . the flowmark workflow manager navigates a path through the process that is determined by start conditions , exit conditions , and transition conditions . connectors link activities in a process model . using connectors , one defines the sequence of activities and the transmission of data between activities . since activities are not executed arbitrarily , they are bound together via control connectors . a control connector might be perceived as a directed edge between two activities ; the activity at the connector &# 39 ; s end point cannot start before the activity at the start point of the connector has finished ( successfully ). control connectors model the potential flow of control within a business process model . default connectors specify where control should flow when no other control connector transition condition evaluates to true . default connectors enable the workflow model to cope with exceptional events . data connectors specify the flow of data in a workflow model . a data connector originates from an activity or a block , and has an activity or a block as its target . one can specify that output data is to go to one target or to multiple targets . a target can have more than one incoming data connector . conditions are the means to specify the flow of control in a process . in flowmark process models , logical expressions can be defined that are evaluated by flowmark at runtime to determine when an activity may start , end , and pass control to the next activity . start conditions are conditions that determine when an activity with incoming control connectors can start . the start condition may specify that all incoming control connectors must evaluate to true , or it may specify that at least one of them must evaluate to true . whatever the start condition , all incoming connectors must be evaluated before the activity can start . if an activity has no incoming control connectors , it becomes ready when the process or block containing it starts . in addition , a boolean expression called transition condition is associated with each control connector . parameters from output containers of activities having already produced their results are followed as parameters referenced in transition conditions . when a runtime activity terminates successfully , all control connectors leaving this activity are determined and the truth value of the associated transition conditions is computed based on the actual values of their parameters . only the end points of control connectors , the transition conditions of which evaluated to true , are considered as activities that might be executed based on the actual context of the business process . transition conditions model thus the context dependent actual flow of control within a business process ( i . e . an instance of a model ). business processes encompass long running activities in general ; such an activity needs to be interrupted . thus , termination of an activity does not necessarily indicate that the associated task has finished successfully . to measure the successfulness of the work performed by an activity , a boolean expression , called exit condition , is associated with each activity . the activities , the exit condition of which evaluated to true in the actual context , are treated as successfully terminated . successfully terminated activities are considered to determine precisely the actual control flow . thus , the logical expression of an exit condition , if specified , must evaluate to true for control to pass from an activity or block . besides describing the potential flow of control and data between activities , a business process model also encompasses the description of the flow of the activities between “ resources ” actually performing the pieces of work represented by each activity . a resource may be specified as a particular program , a person , a role , or an organizational unit . at runtime , tasks are resolved into requests to particular persons to perform particular activities resulting in work items for that person . staff assignments are the means to distribute activities to the right people in the sequence prescribed by the control flow aspect of a business process model . each activity in a process is assigned to one or more staff members defined in the flowmark database . whether an activity is started manually by the user or automatically by the flowmark workflow manager , and whether it requires user interaction to complete or not , a staff member must be assigned to it . a flowmark staff definition entails more than identifying people in a flowmark database . for each person defined , a level , an organization , and multiple roles can be specified . these attributes can be used at runtime to dynamically assign activities to people with suitable attributes . process definition includes modeling of activities , control connectors between the activities , input / output containers , and data connectors . a process is represented as a directed acyclic graph , with the activities as nodes and the control / data connectors as the edges of the graph . the graph is manipulated via a built - in , event - driven , cua compliant graphic editor . the data containers are specified as named data structures . these data structures themselves are specified via the datastructuredefinition facility . flowmark distinguishes three main types of activities : program activities , process activities , and blocks . program activities are implemented through programs . the programs are registered via the program definition facility . blocks contain the same constructs as processes , such as activities , control connectors etc . they are however not named and they have their own exit condition . if the exit condition is not met , the block is started again . the block thus implements a do until construct . process activities are implemented as processes . these subprocesses are defined separately as regular , named processes with all its usual properties . process activities offer great flexibility for process definition . it not only allows the construction of a process through permanent refinement of activities into program and process activities ( top - down ), but also the building of a process out of a set of existing processes ( bottom - up ). in particular , process activities help to organize the modeling work if several process modelers are working together . it allows the team members to work independently on different activities . program and process activities can be associated with a time limit . the time limit specifies how long the activity may take . if the time is exceeded , a designated person is notified . if this person does not react within another time limit , the process administrator is notified . it not only helps to recognize critical situations , but also to detect process deficiencies as all notifications are recorded in an audit trail . all data structures used as templates for the containers of activities and processes are defined via the data structure definition facility . data structures are names and are defined in terms of elementary data types , such as float , integer , or string and references to existing data structures . managing data structures as separate entities has the advantage that all interfaces of activities and their implementations are managed consistently in one place ( similar to header files in programming languages ). all programs which implement program activities are defined via the program registration facility . registered for each program is the name of the program , its location , and the invocation string . the invocation string consists of the program name and the command string passed to the program . before process instances can be created , the process model must be translated to ensure the correctness and completeness of the process model . the translated version of the model is used as a template when a process instance is created . this allows changes to the process model without affecting executing process instances . when a process is started , the start activities are located , the proper people are determined , and the activities are posted onto the work list of the selected people as work items . if a user selects a work item , the activity is executed and removed from the work list of any other user to whom the activity has been posted . after an activity has executed , its exit condition is evaluated . if not met , the activity is rescheduled for execution ; otherwise all outgoing control connectors and the associated transition conditions are evaluated . a control connector is selected if the condition evaluates to true . the target activities of the selected control connectors are then evaluated . if their start conditions are true , they are posted to the work list of selected people . a process is considered terminated if all end activities have completed . to make sure that all end activities finish , a dead path elimination is performed . it removes all edges in the process graph which can never be reached due to failing transition conditions . all information about the current state of a process is stored in the database maintained by the server . this allows for forward recovery in the case of crashes . as already indicated above , wfmss support the definition and execution of business processes . those business processes are made up of a set of activities which are handled by different people at different places ; business processes are therefore processed in most cases in a distributed environment comprising a network of a multitude of computer systems . the activities are generally implemented via programs with which the user interacts and that manage data that is associated with the process . a user typically interacts with the workflow management system via a graphical end user interface that represents the tasks to be performed by the user as icons . work for a particular task is started by the user by double - clicking on the appropriate icon which in turn starts the program implementing the activity . the execution of an activity within a process is performed in two phases visualized in fig1 and fig2 . fig1 shows the first phase in which staff resolution is performed . when a process is defined , each activity is assigned an expression ( staff assignment ) that describes who should perform the activity . the staff assignment is expressed as a query against the organizational database that is part of the workflow management system . when the workflow management system navigates to an activity , it uses that query to find the people who should perform the activity ( staff resolution ). a work item ( 101 , 102 , 103 ) is created for each of the selected persons . depending on some settings , the work item is pushed immediately onto the work list ( 104 , 105 ) of a selected person , or will be made part of the user &# 39 ; s work list as the result of an explicit request . fig2 shows the flow of control when the user starts a work item from the work list representing the second phase of execution of an activity . after double - clicking the work - item representing the execution request of the activity on the work list 201 , the workflow management system materializes the input container 202 and / or output container 203 and activates the program 205 that implements the activity 204 . the program that is executed typically determines it &# 39 ; s context by obtaining some or all of the fields in the input container , interacts with the user , retrieves or modifies some resources / objects 206 , or date data , modifies the context by storing this information in the output container , and then terminates . this constitutes the completion of the activity , and navigation through the process graph continues . it is required that data access must be fast . otherwise , the user is waiting unproductively before any interaction can be performed . thus , the present invention seeks to minimize network traffic during performing said activities . thus , system performance can be enhanced and overall costs reduced . with general reference to the figures and with special reference now to fig3 the essential steps of the method according to the invention are described below . in a first block 110 consisting of steps 112 to 118 , statistical and non - statistical data that form essential conditions and constraints are gathered to gain a base collection of facts that serves as input to the traffic minimization function applied later . therefore , the number and type of database calls which characterize each database &# 39 ; s workload is calculated in a step 112 for each activity and for each table of the distributed relational data base systems being the object to the method of the present invention . workload calculation according to prior art techniques can be applied . it starts with determining the number of process instances that are created in a certain time frame , usually collected during business process modeling . together with the probabilities that exit and transition conditions evaluate to true - it is possible to determine the number of activities that are executed . further , the process distribution is collected . a measure of process concurrency is determined by determining the number of created processes within a given time frame . this information may have already been collected during business modeling , when there are significant peaks in the creation of processes and the overall process is very short . the process creation distribution multiplied by the activity probabilities yields the execution distribution of each of the activities . thus , the workload at program granularity is determined . as a part of creating the activity implementations , the appropriate database access calls are determined . this includes for each sql call the type , such as insert , replace , or delete , the associated table , and the amount of data transported together with the request or being returned as the result of the request . the information about the individual sql calls combined with the activity execution distribution provides for the workload that the database management systems must sustain for each of the databases and tables . combining the derived logical schema with the number of business objects yields the data load for each of the tables . that means the number of rows within each of the tables determines the physical schema , i . e . the number of rows within each of the tables for each of the logical schemes . with reference to fig4 step 114 of fig3 is described in more detail . first , during staff resolution as described above a query 50 against the organizational database 52 is performed to obtain the set 54 of users to whom the activity 56 may be assigned as a work item ( arrow 1 ). next , the workstation the selected users are working on is determined ( arrow 2 ) by accessing the asset database 64 managed by the systems management system . then , it is determined where the activity implementation is running , whether it is the user &# 39 ; s work station 58 or on another computer device 60 as well . this information is usually obtained by the program repository 62 which accesses the asset database 64 . as a result of performing step 114 from fig3 the processors , i . e . the workstations on which the activity implementations run which perform the appropriate database accesses is determined . further , during a step 115 from fig3 the locations are determined where the tables could be placed . this includes existing hardware , or new hardware locations as well , which have to be created to realize the minimization scenario . the next step 116 is to determine the line speed between the processors that run the activity implementations and the potential locations that could hold the database tables . in a next step 117 , the traffic between each of the processors that hold the activity implementation and each of the tables is calculated . the next step 118 is to calculate any traffic that is generated as the result of the operation of the workflow system . fig5 and fig6 respectively , show schematic sketches depicting the database traffic generated by activities a 1 and a 2 that access each a plurality of tables located and managed by respective database management systems dbms 1 , dbms 2 and dbms 3 before and after applying the novel minimization method . before minimizing traffic in the distributed system according to the invention , tables 3 and 4 are located in and managed by dbms 1 , tables 1 , 2 , 5 , 6 , 8 , 9 , 10 are located in and managed by dbms 2 and tables 7 , 11 , 12 , 13 are located in and managed by dbms 3 . a 1 and a 2 are depicted symbolically as circles . included are the respective staff and workstations which are running the activities as described above . while running the activities , a database traffic depicted as arrows 70 , 72 , 74 , 76 , 78 , 80 takes place . this traffic is analyzed by the steps mentioned in block 110 of fig3 . thus , this traffic is the primary subject of the present invention . between a 1 and a 2 an activity related network traffic , i . e . inter - activity traffic 90 , is depicted as thin line 90 . the minimization of this traffic is not performed by the preferred embodiment of the invention because no database accesses are involved . nevertheless , such traffic could be considered by including it as restrictive conditions as described above . applying the traffic minimization function depicted as step 120 in fig3 yields some results describing a new placement of the tables as is depicted in fig6 . analysis of the minimization data may have shown in this example that for both workstations included in the circles of a 1 and a 2 , the bandwidth and line speed is best on the data connection 70 and 80 . so , dbms 1 should be considered as a local dbms for both , a 1 and a 2 . “ local ” means high bandwidth connections or residence at the same physical node . as most of the tables , i . e . tables 1 , 2 , 3 , 4 , 10 , 12 , 13 are most frequently accessed by activities a 1 and a 2 , these tables are re - arranged from dbms 2 and dbms 3 , respectively , onto dbms 1 according to the invention , following the goal of placing tables such that most traffic is as ‘ local ’ as possible for each workstation and activity . other activities not depicted in the figures frequently access tables 5 , 6 , 7 , 8 in dbms 2 and tables 9 , 11 in dbms 3 . further , bandwidth and line speed on connections 72 , 74 , 76 , 78 are not as good as that of connections 70 and 80 . as these facts and further facts that were collected in block 110 were included in the minimization method , table 7 is re - arranged from dbms 3 to dbms 2 , and table 9 is re - arranged from dbms 2 to dbms 3 . as seen from the above , with all necessary data collected in block 110 , it can be calculated where the appropriate tables should be placed so that the network traffic is minimized . the minimizing problem can not be solved exactly if there are a large number of tables and processors involved . however heuristic approaches have been developed over time that allow the determination of a solution that is sufficiently exact to correspond to the inexactness implied by the inexact numbers used as input . to focus on the kernel of the present invention the outlined calculation has been simplified . the following arguments , however , have to be considered , if applicable : it is assumed that the processors that run the database management system are capable of potentially handling the complete load . if this is not the case , additional restrictions must be considered . the network traffic is solely created by the workflow system and the activity implementations . if other applications generate additional network traffic , this must be considered , as well . sql calls that involve multiple tables , such as joins , may use tables that are managed by different database management systems . in this case the database management systems must exchange data . the appropriate information can be derived from the data load and the way the optimizer of the database management systems work . this must also be factored into the network traffic . the method described above can be incorporated in a program that is coupled with the process models underlying the business processes to be performed in the networked computer system . as seen from above , the method according to the invention can be derived from the process model of the distributed applications . the invention has been described with reference to a specific exemplary embodiment . it will be evident that various modifications and changes may be made thereto without departing from the spirit and scope of the invention as set forth in the appended claims . the specification and drawings are to be regarded as illustrative rather than restrictive .