Creating and running a Red Hat Business Optimizer solver for employee rostering using Business Central

Red Hat Process Automation Manager 7.0

Red Hat Customer Content Services

brms-docs@redhat.com

Abstract

This document describes how to create and run the employee rostering example for Red Hat Business Optimizer using Business Central in Red Hat Process Automation Manager 7.0.

Preface

As a business rules developer, you can test and interact with the Red Hat Business Optimizer functionality using the preconfigured employee-rostering sample project included in the Red Hat Process Automation Manager distribution.

The employee-rostering sample project can be built and deployed in Business Central. The project is designed to demonstrate how to create each of the Business Central assets required to solve the shift rostering planning problem and use Red Hat Business Optimizer to find the best possible solution. Use this document to deploy the preconfigured employee-rostering project in Business Central, or to create the project yourself using Business Central.

Note

The employee-rostering sample project in Business Central does not include a data set.

Prerequisites

Red Hat JBoss Enterprise Application Platform 7.1.0 installed. See Red Hat JBoss EAP 7.1.0 Installation Guide.
Red Hat Process Automation Manager installed. For more information, see Planning a Red Hat Process Automation Manager installation.
Red Hat Process Automation Manager is running and you can log in to Business Central with the admin role. For more information, see Planning a Red Hat Process Automation Manager installation.
Red Hat Process Automation Manager is configured for Red Hat Business Optimizer.
If you are modifying this example to optimize your own data, a data set is required in order to run an optimization task on the Decision Server after the modified project has been deployed from Business Central to the server.

Chapter 1. Deploy the employee rostering sample project in Business Central

Business Central includes a number of sample projects that you can use to get familiar with the product and its features. The employee rostering sample project has been designed and created to demonstrate the shift rostering use case for Red Hat Business Optimizer. Use the following procedure to deploy and run the employee rostering sample in Business Central.

Prerequisites

Red Hat Process Automation Manager has been downloaded and installed. For installation options, see Planning a Red Hat Process Automation Manager installation.
You have started the decision server and logged in to Business Central with a user that has admin permissions. For more information about getting started, see Getting started with decision services.

Procedure

In Business Central, click Menu → Design → Projects.
In the preconfigured myteam space, click Try Samples.
Select employee-rostering from the list of sample projects and click Ok in the upper-right corner to import the project.
After the asset list has complied, click Build & Deploy to deploy the employee rostering example.

The rest of this document explains each of the project assets and their configuration.

Chapter 2. Set up the employee rostering sample project

The employee rostering sample project is a preconfigured project available in Business Central. You can learn about how to deploy this project in Chapter 1, Deploy the employee rostering sample project in Business Central.

This chapter describes how to set up the employee rostering example. You can use the workflow in this example to create a similar project of your own in Business Central.

Prerequisites

Red Hat Process Automation Manager has been downloaded and installed.
You have deployed Business Central and logged in with a user that has the admin role.

Procedure

Create a new project in Business Central by clicking Menu → Design → Projects → Add Project.
In the Add Project window, fill out the following fields:
- Name: employee-rostering
- Description(optional): Employee rostering problem optimization using Business Optimizer. Assigns employees to shifts based on their skill.
Optionally, click Show Advanced Options to populate the Group ID, Artifact ID, and Version information.
- Group ID: employeerostering
- Artifact ID: employeerostering
- Version: 1.0.0-SNAPSHOT
Click Add to add the project to the Business Central project repository.

Chapter 3. Problem facts and planning entities

Each of the domain classes in the employee rostering planning problem can be categorized as one of the following:

A unrelated class: not used by any of the score constraints. From a planning standpoint, this data is obsolete.
A problem fact class: used by the score constraints, but does not change during planning (as long as the problem stays the same), for example, Shift and Employee. All the properties of a problem fact class are problem properties.
A planning entity class: used by the score constraints and changes during planning, for example, ShiftAssignment. The properties that change during planning are planning variables. The other properties are problem properties.
Ask yourself the following questions:
What class changes during planning?
Which class has variables that I want the Solver to change?
That class is a planning entity.
A planning entity class needs to be annotated with the @PlanningEntity annotation, or defined in Business Central using the Red Hat Business Optimizer dock in the domain designer.
Each planning entity class has one or more planning variables, and should also have one or more defining properties.
Most use cases have only one planning entity class, and only one planning variable per planning entity class.

Chapter 4. Create the data model for the employee rostering project

Use this section to create the data objects required to run the employee rostering sample project in Business Central.

Prerequisite

You have completed the project set up described in Chapter 2, Set up the employee rostering sample project.

Procedure

With your new project, either click Data Object in the project perspective, or click Add Asset → Data Object to create a new data object.
Name the first data object Timeslot, and select employeerostering.employeerostering as the Package.
Click Ok.
In the Data Objects perspective, click +add field to add fields to the Timeslot data object.
In the id field, type endTime.
Click the drop-down menu next to Type and select LocalDateTime.
Click Create and continue to add another field.
Add another field with the id startTime and Type LocalDateTime.
Click Create.
Click Save in the upper-right corner to save the Timeslot data object.
Click the x in the upper-right corner to close the Data Objects perspective and return to the Assets menu.

Using the previous steps, create the following data objects and their attributes:

Table 4.1. Skill

id	Type
`name`	`String`

Table 4.2. Employee

id	Type
`name`	`String`
`skills`	`employeerostering.employeerostering.Skill[List]`

Table 4.3. Shift

id	Type
`requiredSkill`	`employeerostering.employeerostering.Skill`
`timeslot`	`employeerostering.employeerostering.Timeslot`

Table 4.4. DayOffRequest

id	Type
`date`	`LocalDate`
`employee`	`employeerostering.employeerostering.Employee`

Table 4.5. ShiftAssignment

id	Type
`employee`	`employeerostering.employeerostering.Employee`
`shift`	`employeerostering.employeerostering.Shift`

For more examples of creating data objects, see Getting started with decision services.

4.1. Create the employee roster planning entity

In order to solve the employee rostering planning problem, you must create a planning entity and a solver. The planning entity is defined in the domain designer using the attributes available in the Red Hat Business Optimizer dock.

Use the following procedure to define the ShiftAssignment data object as the planning entity for the employee rostering example.

Prerequisite

You have created the relevant data objects and planning entity required to run the employee rostering example by completing the procedures in Chapter 4, Create the data model for the employee rostering project.

Procedure

From the project Assets menu, open the ShiftAssignment data object.
In the Data Objects perspective, open the Red Hat Business Optimizer dock by clicking the on the right.
Select Planning Entity.
Select employee from the list of fields under the ShiftAssignment data object.
In the Red Hat Business Optimizer dock, select Planning Variable.
In the Value Range Id input field, type employeeRange. This adds the @ValueRangeProvider annotation to the planning entity, which you can view by clicking the Source tab in the designer.
The value range of a planning variable is defined with the @ValueRangeProvider annotation. A @ValueRangeProvider annotation always has a property id, which is referenced by the @PlanningVariable property valueRangeProviderRefs.
Close the dock and click Save to save the data object.

4.2. Create the employee roster planning solution

The employee roster problem relies on a defined planning solution. The planning solution is defined in the domain designer using the attributes available in the Red Hat Business Optimizer dock.

Prerequisite

You have created the relevant data objects and planning entity required to run the employee rostering example by completing the procedures in Chapter 4, Create the data model for the employee rostering project and Section 4.1, “Create the employee roster planning entity”.

Procedure

Create a new data object with the identifier EmployeeRoster.

Create the following fields:

Table 4.6. EmployeeRoster

id	Type
`dayOffRequestList`	`employeerostering.employeerostering.DayOffRequest[List]`
`shiftAssignmentList`	`employeerostering.employeerostering.ShiftAssignment[List]`
`shiftList`	`employeerostering.employeerostering.Shift[List]`
`skillList`	`employeerostering.employeerostering.Skill[List]`
`timeslotList`	`employeerostering.employeerostering.Timeslot[List]`

In the Data Objects perspective, open the Red Hat Business Optimizer dock by clicking the on the right.
Select Planing Solution.
Leave the default Hard soft score as the Solution Score Type. This automatically generates a score field in the EmployeeRoster data object with the solution score as the type.
Add a new field with the following attributes:
id Type

employeeList

employeerostering.employeerostering.Employee[List]
With the employeeList field selected, open the Red Hat Business Optimizer dock and select the Planning Value Range Provider box.
In the id field, type employeeRange. Close the dock.
Click Save in the upper-right corner to save the asset.

id	Type
`employeeList`	`employeerostering.employeerostering.Employee[List]`

Chapter 5. Employee rostering constraints

Employee rostering is a planning problem. All planning problems include constraints that must be satisfied in order to find an optimal solution.

The employee rostering sample project in Business Central includes the following hard and soft constraints:

Hard constraint

Employees are only assigned one shift per day.
All shifts that require a particular employee skill are assigned an employee with that particular skill.

Soft constraints

All employees are assigned a shift.
If an employee requests a day off, their shift can be reassigned to another employee.

Hard and soft constraints can be defined in Business Central using either the free-form DRL designer, or using guided rules.

5.1. DRL (Drools Rule Language) rules

DRL (Drools Rule Language) rules are business rules that you define directly in .drl text files. These DRL files are the source in which all other rule assets in Business Central are ultimately rendered. You can create and manage DRL files within the Business Central interface, or create them externally using Red Hat Developer Studio, Java objects, or Maven archetypes. A DRL file can contain one or more rules that define at minimum the rule conditions (when) and actions (then). The DRL designer in Business Central provides syntax highlighting for Java, DRL, and XML.

All data objects related to a DRL rule must be in the same project package as the DRL rule in Business Central. Assets in the same package are imported by default. Existing assets in other packages can be imported with the DRL rule.

5.2. Constraint definition for employee rostering using the DRL designer

You can create constraint definitions for the employee rostering example using the free-form DRL designer in Business Central.

Use this procedure to create a hard constraint where no employee can be assigned a shift that begins less than 10 hours after their previous shift ended.

Procedure

Go to Menu → Design → Projects and click the project name.
Click Add Asset → DRL file.
In the DRL file name field, type ComplexScoreRules.
Select the employeerostering.employeerostering package.
Click +Ok to create the DRL file.

In the Model tab of the DRL designer, define the Employee10HourShiftSpace rule as a DRL file:

package employeerostering.employeerostering;

rule "Employee10HourShiftSpace"
    dialect "mvel"
    when
        $shiftAssignment : ShiftAssignment( $employee : employee != null, $shiftEndDateTime : shift.timeslot.endTime)
        ShiftAssignment( this != $shiftAssignment, $employee == employee, $shiftEndDateTime <= shift.timeslot.endTime,
                $shiftEndDateTime.until(shift.timeslot.startTime, java.time.temporal.ChronoUnit.HOURS) <10)
    then
        scoreHolder.addHardConstraintMatch(kcontext, -1);
end

Click Save to save the DRL file.

For more information about creating DRL files, see Designing a decision service using DRL rules.

Chapter 6. Create rules for employee rostering using guided rules

You can create rules that define hard and soft constraints for employee rostering using the guided rules designer in Business Central.

6.1. Guided rules

Guided rules are business rules that you create in a UI-based guided rules designer in Business Central that leads you through the rule-creation process. The guided rules designer provides fields and options for acceptable input based on the data objects for the rule being defined. The guided rules that you define are compiled into Drools Rule Language (DRL) rules as with all other rule assets.

All data objects related to a guided rule must be in the same project package as the guided rule. Assets in the same package are imported by default. After you create the necessary data objects and the guided rule, you can use the Data Objects tab of the guided rules designer to verify that all required data objects are listed or to import other existing data objects by adding a New item.

6.2. Create a guided rule to balance employee shift numbers

The BalanceEmployeesShiftNumber guided rule creates a soft constraint that ensures shifts are assigned to employees in a way that is balanced as evenly as possible. It does this by creating a score penalty that increases when shift distribution is less even. The score formula, implemented by the rule, incentivizes the Solver to distribute shifts in a more balanced way.

Procedure

Go to Menu → Design → Projects and click the project name.
Click Add Asset → Guided Rule.
Enter BalanceEmployeesShiftNumber as the Guided Rule name and select the employeerostering.employeerostering Package.
Click Ok to create the rule asset.
Add a WHEN condition by clicking the in the WHEN field.
Select Employee in the Add a condition to the rule window. Click +Ok.
Click on the Employee condition to modify the constraints and add the variable name $employee.
Add the WHEN condition From Accumulate.
1. Above the From Accumulate condition, click click to add pattern and select Number as the fact type from the drop-down list.
2. Add the variable name $shiftCount to the Number condition.
3. Below the From Accumulate condition, click click to add pattern and select the ShiftAssignment fact type from the drop-down list.
4. Add the variable name $shiftAssignment to the ShiftAssignment fact type.
5. Click on the ShiftAssignment condition again and from the Add a restriction on a field drop-down list, select employee.
6. Select equal to from the drop-down list next to the employee constraint.
7. Click the icon next to the drop-down button to add a variable, and click Bound variable in the Field value window.
8. Select $employee from the drop-down list.
9. In the Function box type count($shiftAssignment).
Add the THEN condition by clicking the in the THEN field.
Select Modify Soft Score in the Add a new action window. Click +Ok.
1. Type the following expression into the box: -($shiftCount.intValue()*$shiftCount.intValue())
Click Validate in the upper-right corner to check all rule conditions are valid. If the rule validation fails, address any problems described in the error message, review all components in the rule, and try again to validate the rule until the rule passes.
Click Save to save the rule.

For more information about creating guided rules, see Designing a decision service using guided rules.

6.3. Create a guided rule for no more than one shift per day

The OneEmployeeShiftPerDay guided rule creates a hard constraint that employees are not assigned more than one shift per day. In the employee rostering example, this constraint is created using the guided rule designer.

Procedure

Go to Menu → Design → Projects and click the project name.
Click Add Asset → Guided Rule.
Enter OneEmployeeShiftPerDay as the Guided Rule name and select the employeerostering.employeerostering Package.
Click Ok to create the rule asset.
Add a WHEN condition by clicking the in the WHEN field.
Select Free form DRL from the Add a condition to the rule window.

In the free form DRL box, type the following condition:

$shiftAssignment : ShiftAssignment( employee != null )
		ShiftAssignment( this != $shiftAssignment , employee == $shiftAssignment.employee , shift.timeslot.startTime.toLocalDate() == $shiftAssignment.shift.timeslot.startTime.toLocalDate() )

This condition states that a shift cannot be assigned to an employee that already has another shift assignment on the same day.

Add the THEN condition by clicking the in the THEN field.
Select Add free form DRL from the Add a new action window.
In the free form DRL box, type the following condition:
```
scoreHolder.addHardConstraintMatch(kcontext, -1);
```
Click Validate in the upper-right corner to check all rule conditions are valid. If the rule validation fails, address any problems described in the error message, review all components in the rule, and try again to validate the rule until the rule passes.
Click Save to save the rule.

For more information about creating guided rules, see Designing a decision service using guided rules.

6.4. Create a guided rule to match skills to shift requirements

The ShiftReqiredSkillsAreMet guided rule creates a hard constraint that ensures all shifts are assigned an employee with the correct set of skills. In the employee rostering example, this constraint is created using the guided rule designer.

Procedure

Go to Menu → Design → Projects and click the project name.
Click Add Asset → Guided Rule.
Enter ShiftReqiredSkillsAreMet as the Guided Rule name and select the employeerostering.employeerostering Package.
Click Ok to create the rule asset.
Add a WHEN condition by clicking the in the WHEN field.
Select ShiftAssignment in the Add a condition to the rule window. Click +Ok.
Click on the ShiftAssignment condition, and select employee from the Add a restriction on a field drop-down list.
In the designer, click the drop-down list next to employee and select is not null.
Click on the ShiftAssignment condition, and click Expression editor.
1. In the designer, click [not bound] to open the Expression editor, and bind the expression to the variable $requiredSkill. Click Set.
2. In the designer, next to $requiredSkill, select shift from the first drop-down list, then requiredSkill from the next drop-down list.
Click on the ShiftAssignment condition, and click Expression editor.
1. In the designer, next to [not bound], select employee from the first drop-down list, then skills from the next drop-down list.
2. Leave the next drop-down list as Choose.
3. In the next drop-down box, change please choose to excludes.
4. Click the icon next to excludes, and in the Field value window, click the New formula button.
5. Type $requiredSkill into the formula box.
Add the THEN condition by clicking the in the THEN field.
Select Modify Hard Score in the Add a new action window. Click +Ok.
Type -1 into the score actions box.
Click Validate in the upper-right corner to check all rule conditions are valid. If the rule validation fails, address any problems described in the error message, review all components in the rule, and try again to validate the rule until the rule passes.
Click Save to save the rule.

For more information about creating guided rules, see Designing a decision service using guided rules.

6.5. Create a guided rule to manage day off requests

The DayOffRequest guided rule creates a soft constraint that allows a shift to be reassigned to another employee in the event the employee who was originally assigned the shift is no longer able to work that day. In the employee rostering example, this constraint is created using the guided rule designer.

Procedure

Go to Menu → Design → Projects and click the project name.
Click Add Asset → Guided Rule.
Enter DayOffRequest as the Guided Rule name and select the employeerostering.employeerostering Package.
Click Ok to create the rule asset.
Add a WHEN condition by clicking the in the WHEN field.
Select Free form DRL from the Add a condition to the rule window.
In the free form DRL box, type the following condition:
```
$dayOffRequest : DayOffRequest( )
		ShiftAssignment( employee == $dayOffRequest.employee , shift.timeslot.startTime.toLocalDate() == $dayOffRequest.date )
```
This condition states if a shift is assigned to an employee who has made a day off request, the employee can be unassigned the shift on that day.
Add the THEN condition by clicking the in the THEN field.
Select Add free form DRL from the Add a new action window.
In the free form DRL box, type the following condition:
```
scoreHolder.addSoftConstraintMatch(kcontext, -100);
```
Click Validate in the upper-right corner to check all rule conditions are valid. If the rule validation fails, address any problems described in the error message, review all components in the rule, and try again to validate the rule until the rule passes.
Click Save to save the rule.

For more information about creating guided rules, see Designing a decision service using guided rules.

Chapter 7. Configure the Solver for employee rostering

You can create and edit Solver configurations in Business Central. The Solver configuration designer creates a solver configuration that can be run after the project is deployed.

Prerequisite

Red Hat Process Automation Manager has been downloaded and installed. You have created and configured all of the relevant assets for the employee rostering example.

Procedure

In Business Central, click Menu → Projects, and click on your project to open it.
In the Assets perspective, click Add Asset → Solver configuration
In the Create new Solver configuration window, type the name EmployeeRosteringSolverConfig for your Solver and click Ok.
This opens the Solver configuration designer.
In the Score Director Factory configuration section, define a knowledge base that contains scoring rule definitions. The employee rostering sample project uses defaultKieBase.
1. Select one of the knowledge sessions defined within the knowledge base. The employee rostering sample project uses defaultKieSession.
Click Validate in the upper-right corner to check the Score Director Factory configuration is correct. If validation fails, address any problems described in the error message, and try again to validate until the configuration passes.
Click Save to save the Solver configuration.

7.1. Configure Solver termination for the employee rostering project

You can configure the Solver to terminate after a specified amount of time. By default, the planning engine is given an unlimited time period to solve a problem instance.

The employee rostering sample project is set up to run for 30 seconds.

Prerequisite

You have created all relevant assets for the employee rostering project and created the EmployeeRosteringSolverConfig solver configuration in Business Central as described in Chapter 7, Configure the Solver for employee rostering.

Procedure

Open the EmployeeRosteringSolverConfig from the Assets perspective. This will open the Solver configuration designer.
In the Termination section, click Add to create new termination element within the selected logical group.
Select the Time spent termination type from the drop-down list. This is added as an input field in the termination configuration.
Use the arrows next to the time elements to adjust the amount of time spent to 30 seconds.
Click Validate in the upper-right corner to check the Score Director Factory configuration is correct. If validation fails, address any problems described in the error message, and try again to validate until the configuration passes.
Click Save to save the Solver configuration.

For more information about configuring a Solver or Solver termination, see Red Hat Process Automation Manager Red Hat Business Optimizer Guide.

7.2. Register the Solver using the REST API

Once the solver configuration is created and the project is deployed to the decision server, you can create a Solver and submit planning problems. This can be done by accessing the project KIE container’s capabilities through the decision server’s remote APIs. You can create a Solver from the solver configuration file, then submit a planning problem to it and request the best solution at any time.

Each Solver is capable of optimizing one planning problem at a time.

Prerequisites

The employee rostering project has been set up and deployed according to the previous chapters in this document.
The Solver has been configured as instructed in Chapter 7, Configure the Solver for employee rostering and Section 7.1, “Configure Solver termination for the employee rostering project”.
You have successfully built and deployed the employee rostering project. For more information about deploying the employee rostering sample project in the workbench, see Chapter 1, Deploy the employee rostering sample project in Business Central.

Procedure

Create a HTTP request using the following header:

authorization: admin:admin
X-KIE-ContentType: xstream
content-type: application/xml

Register the Solver using the following request:
PUT
http://localhost:8080/kie-server/services/rest/server/containers/employeerostering_1.0.0-SNAPSHOT/solvers/EmployeeRosteringSolver
Request body
```
<solver-instance>
  <solver-config-file>employeerostering/employeerostering/EmployeeRosteringSolverConfig.solver.xml</solver-config-file>
</solver-instance>
```

Submit a request to the Solver:

POST

http://localhost:8080/kie-server/services/rest/server/containers/employeerostering_1.0.0-SNAPSHOT/solvers/EmployeeRosteringSolver/state/solving

Request body

<employeerostering.employeerostering.EmployeeRoster>
  <employeeList>
    <employeerostering.employeerostering.Employee>
      <name>John</name>
      <skills>
        <employeerostering.employeerostering.Skill>
          <name>reading</name>
        </employeerostering.employeerostering.Skill>
      </skills>
    </employeerostering.employeerostering.Employee>
    <employeerostering.employeerostering.Employee>
      <name>Mary</name>
      <skills>
        <employeerostering.employeerostering.Skill>
          <name>writing</name>
        </employeerostering.employeerostering.Skill>
      </skills>
    </employeerostering.employeerostering.Employee>
    <employeerostering.employeerostering.Employee>
      <name>Petr</name>
      <skills>
        <employeerostering.employeerostering.Skill>
          <name>speaking</name>
        </employeerostering.employeerostering.Skill>
      </skills>
    </employeerostering.employeerostering.Employee>
  </employeeList>
  <shiftList>
    <employeerostering.employeerostering.Shift>
      <timeslot>
        <startTime>2017-01-01T00:00:00</startTime>
        <endTime>2017-01-01T01:00:00</endTime>
      </timeslot>
      <requiredSkill reference="../../../employeeList/employeerostering.employeerostering.Employee/skills/employeerostering.employeerostering.Skill"/>
    </employeerostering.employeerostering.Shift>
    <employeerostering.employeerostering.Shift>
      <timeslot reference="../../employeerostering.employeerostering.Shift/timeslot"/>
      <requiredSkill reference="../../../employeeList/employeerostering.employeerostering.Employee[3]/skills/employeerostering.employeerostering.Skill"/>
    </employeerostering.employeerostering.Shift>
    <employeerostering.employeerostering.Shift>
      <timeslot reference="../../employeerostering.employeerostering.Shift/timeslot"/>
      <requiredSkill reference="../../../employeeList/employeerostering.employeerostering.Employee[2]/skills/employeerostering.employeerostering.Skill"/>
    </employeerostering.employeerostering.Shift>
  </shiftList>
  <skillList>
    <employeerostering.employeerostering.Skill reference="../../employeeList/employeerostering.employeerostering.Employee/skills/employeerostering.employeerostering.Skill"/>
    <employeerostering.employeerostering.Skill reference="../../employeeList/employeerostering.employeerostering.Employee[3]/skills/employeerostering.employeerostering.Skill"/>
    <employeerostering.employeerostering.Skill reference="../../employeeList/employeerostering.employeerostering.Employee[2]/skills/employeerostering.employeerostering.Skill"/>
  </skillList>
  <timeslotList>
    <employeerostering.employeerostering.Timeslot reference="../../shiftList/employeerostering.employeerostering.Shift/timeslot"/>
  </timeslotList>
  <dayOffRequestList/>
  <shiftAssignmentList/>
</employeerostering.employeerostering.EmployeeRoster>

Request the best solution to the planning problem:

GET

http://localhost:8080/kie-server/services/rest/server/containers/employeerostering_1.0.0-SNAPSHOT/solvers/EmployeeRosteringSolver/bestsolution

Example response

<solver-instance>
  <container-id>employee-rostering</container-id>
  <solver-id>solver1</solver-id>
  <solver-config-file>employeerostering/employeerostering/EmployeeRosteringSolverConfig.solver.xml</solver-config-file>
  <status>NOT_SOLVING</status>
  <score scoreClass="org.optaplanner.core.api.score.buildin.hardsoft.HardSoftScore">0hard/0soft</score>
  <best-solution class="employeerostering.employeerostering.EmployeeRoster">
    <employeeList>
      <employeerostering.employeerostering.Employee>
        <name>John</name>
        <skills>
          <employeerostering.employeerostering.Skill>
            <name>reading</name>
          </employeerostering.employeerostering.Skill>
        </skills>
      </employeerostering.employeerostering.Employee>
      <employeerostering.employeerostering.Employee>
        <name>Mary</name>
        <skills>
          <employeerostering.employeerostering.Skill>
            <name>writing</name>
          </employeerostering.employeerostering.Skill>
        </skills>
      </employeerostering.employeerostering.Employee>
      <employeerostering.employeerostering.Employee>
        <name>Petr</name>
        <skills>
          <employeerostering.employeerostering.Skill>
            <name>speaking</name>
          </employeerostering.employeerostering.Skill>
        </skills>
      </employeerostering.employeerostering.Employee>
    </employeeList>
    <shiftList>
      <employeerostering.employeerostering.Shift>
        <timeslot>
          <startTime>2017-01-01T00:00:00</startTime>
          <endTime>2017-01-01T01:00:00</endTime>
        </timeslot>
        <requiredSkill reference="../../../employeeList/employeerostering.employeerostering.Employee/skills/employeerostering.employeerostering.Skill"/>
      </employeerostering.employeerostering.Shift>
      <employeerostering.employeerostering.Shift>
        <timeslot reference="../../employeerostering.employeerostering.Shift/timeslot"/>
        <requiredSkill reference="../../../employeeList/employeerostering.employeerostering.Employee[3]/skills/employeerostering.employeerostering.Skill"/>
      </employeerostering.employeerostering.Shift>
      <employeerostering.employeerostering.Shift>
        <timeslot reference="../../employeerostering.employeerostering.Shift/timeslot"/>
        <requiredSkill reference="../../../employeeList/employeerostering.employeerostering.Employee[2]/skills/employeerostering.employeerostering.Skill"/>
      </employeerostering.employeerostering.Shift>
    </shiftList>
    <skillList>
      <employeerostering.employeerostering.Skill reference="../../employeeList/employeerostering.employeerostering.Employee/skills/employeerostering.employeerostering.Skill"/>
      <employeerostering.employeerostering.Skill reference="../../employeeList/employeerostering.employeerostering.Employee[3]/skills/employeerostering.employeerostering.Skill"/>
      <employeerostering.employeerostering.Skill reference="../../employeeList/employeerostering.employeerostering.Employee[2]/skills/employeerostering.employeerostering.Skill"/>
    </skillList>
    <timeslotList>
      <employeerostering.employeerostering.Timeslot reference="../../shiftList/employeerostering.employeerostering.Shift/timeslot"/>
    </timeslotList>
    <dayOffRequestList/>
    <shiftAssignmentList/>
    <score>0hard/0soft</score>
  </best-solution>
</solver-instance>

Appendix A. Versioning information

Documentation last updated on: Monday, October 1, 2018.

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