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Scheduling
Prepared by:Akın ÖzkanBurcu UzmanMeryem Zümra YıldızSemih Yaraşık
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Content1. Definition of Scheduling
1.1. Components of Scheduling1.2. Where to use?1.3. Estimation
2. Gantt Chart MS Project
3. Precedence Diagrams or Networks3.1. First and Last Events 3.2. Types of Network Diagrams3.3. Dummy Activities3.4. AON vs. AOA3.5. Schedule Network Methodology3.6. Start Event3.7. LOGON Task Table & AON Diagram3.8. Incorrect AOA Example3.9. Key Features of Schedule Networks3.10. An Example of Early and Late Times for AON3.11. Network Methods
4. Our Company 4.1. Company Profile 4.2. Definition of Project
5. Scheduling of Our Project 5.1. Work Breakdown Structure5.2. Work Packages5.3. Gantt Chart5.4. Critical Path
6. Reference List
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Sharing always results in contention
A scheduling discipline resolves contention:
who’s next ?
1. Key to fairly sharing resources and providing performance guarantees
2. Split project into tasks (= create a WBS)3. Estimate time and resources required to complete each task.4. Organize tasks concurrently to make optimal use of
workforce.5. Minimize task dependencies to avoid delays caused by one
task waiting for another to complete.6. Dependent on project managers intuition and experience.
1. Definition
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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1. DefinitionProject scheduling involves,
Estimated start time
Required completion time
WBS (Work Breakdown Structure)
Scheduling the activities
Allocating owners and resources
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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1.1. Components of SchedulingA scheduling discipline does two things:
decides service order manages queue of service request
Example: Consider queries awaiting web server scheduling discipline decides service order and also if some query should be ignored.
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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1.2. Where to use? Anywhere where contention may occur
At every layer of protocol stack
Usually studied at network layer, at output queues of switches
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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1.3. EstimationActivities/task characterized by:
Effort: how much work will the activity need to be completed
Resources: how many resources will be working on the activity
Duration: how long will the activity last for
… estimation technique provide (at least) two of the quantities specified above
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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Effort
1.3. Estimation
Your best shot for providing estimations (how complex/how much work does the activity require?)
Measured in man/month
Mind you though: communication increases the time to complete activities
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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Resources
1.3. Estimation
The best point is to determine how many resources will work in the activity
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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Duration
1.3. Estimation
How much time will the activity last for
Measured in (work-)hours, (work-)days, (work) months, …
Calendar time != duration: calendar time includes non-working days, holidays, …
Usually: A duration of 5 days == 40 hours (8 hours a day) = 1
calendar week (sat and sun rest time)
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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2. Gantt Chart Gantt Chart is a way to graphically show progress of a project. Gantt chart is useful tool for planning and scheduling projects.
A Gantt chart is helpful when monitoring a project's progress.
With Gantt chart, all subtasks of a task can be viewed graphically.
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
A Gantt chart showing three kinds of schedule dependencies (in red) and percent complete indications
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A Gantt chart created using Microsoft Project (MSP). Note (1) the critical path is in red, (2) the slack is the black lines connected to non-critical activities, (3) since Saturday and Sunday are not work days and are thus excluded from the schedule, some bars on the Gantt chart are longer if they cut through a weekend.
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2. Gantt Chart Example
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3. Precedence Diagrams or Networks Shows tasks and their relationships.
Exposes tasks that must be completed before others. Called a precedence diagram. Arrows show how tasks are ordered and flow of time.
Key elements include determining predecessors and defining attributes such as:
early start date last-last early finish date late finish date Duration WBS reference
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.1. First and Last Events First event has no predecessors
Last event has no successors
All networks have a first and last event.
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.2. Types of Network Diagrams
Activity on Node (AON) Used in CPM
Activity on Arc (AOA)Used in PERT
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.2.1. Activity on Node (AON) Diagrams “Bubble Chart”
The most common information shown is:
The activity name The normal duration time The early start time (ES) The early finish time (EF) The late start time (LS) The late finish time (LF) The slack
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.2.1. AON Chart based on Activities and Predecessors
A network diagram created using Microsoft Project (MSP). Note the critical path is in red.
A node like this one (from Microsoft Visio) can be used to display the activity name, duration, ES, EF, LS, LF, and slack1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.2.2. Activity on Arc (AOA) Diagrams
Events are in bubbles.
Activities represented by lines or “arcs” Delimited by Bubbles (Events)
Requires “Dummy” Activities to illustrate precedence
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.2.2. Activity on Arc (Arrow) Diagrams
14 15
“Start”
event
“Finish”
event
8 weeks
Activity Y:
Final installation
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
In the network diagram shown, each arc represents an activity and is labelled with the
activity number .This network is an activity on arc (AOA) network.
The nodes of the network represent the start (and end) of activities and are regarded as events.
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3.3. Dummy ActivitiesDummy Activity: Represents a dependency between tasks
which doesn’t represent any activity.1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List When two paths in an activity network (edges as activities) have a common event but are independent,
or partly independent of one another, it is necessary to introduce a dummy activity,
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3.4. AON vs. AOA AON networks do not use dummy events
Simpler and easier to generate than AOA Popular in Construction Industry
AOA method places emphasis on “Events” Developed before AON Better for “PERT” charts AOA line segments imply “flow of time Look similar to Gantt Charts
Most Software packages create both
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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We are only interested in Process
3.5. Schedule Network Methodology Tabulate Tasks (Activities)
Determine Task Duration
Determine Immediate Predecessors
Assign Start Event Date and Time
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.6. Start Event Establish Start Date
Calculate all other event dates using Schedule Logic and Task Duration
Schedule network determines dates, not the other way around
If finish date is incompatible with project goals, you must adjust the schedule assumptions
Logic (Workarounds) Task Duration (More People or Overtime)
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.7. LOGON Task Table
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.7. LOGON AON Diagram
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.8. Incorrect AOA Example
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.9. Key Features of Schedule Networks Critical Path
Early Times Start Finish
Late Time Start Finish
Total Slack
Free Slack
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.9.1. Critical Path Concept of “Path Length” through network
Calculate for all possible paths by traversing Network from left to right
Longest path length from start event to finish event is critical path
Activities on the critical path cause a day-for-day slip in the completion event
After calculating the critical path, look for things that can be done in parallel
Shortens critical path
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.9.1. LOGON Critical Path Determination
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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3.9.2. Early Expected Time of an Event Designated as TE
Calculation of Early Expected Time is part of schedule analysis
Events which are not on the critical path can be started early By definition, events on the critical path cannot be
started early Can have more than one critical path, on that path
events cannot be started early
Calculated by taking the sum of all task durations on the longest path leading to the event
Traverse network from left to right
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.9.2. Early Expected Time Determination
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.9.3. Latest Allowable Time of an Event Designated as TL
Latest time to which an event can be slipped without affecting succeeding events
Calculated by taking the sum of all task durations on the longest backward path from the finish date to the event of interest
Traverse network from right to left
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.9.3. Latest Allowable Time Determination
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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3.9.4. Total Slack Slack is the range of allowable time between when a task
can be started, and when it must be started Once slack is used up, the finish date of the project is
affected The task of interest is now on the critical path
Total slack of an activity is the amount of slack available to all activities on a given subpath of a network
Total slack of activities on the critical path is zero
Total Slack of an activity (task) is calculated as follows:
Total Slack = LS - ES
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.9.5. Free Slack Activities not on the critical path can be delayed without
affecting the start time of succeeding tasks Free slack of an activity is the amount of time that the activity
can slip without affecting its successors Assumes that the TE of all preceding tasks has been
met Free Slack of an activity is calculated as follows:
Free Slack = ES (earliest successor) - EF
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.10. An Example of Early and Late Times for AON
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
3.11. Network Methods CPM (Critical Path Method)
PDM (Precedence Diagramming Method)
MPM (Metra Potential Method)
PERT (Program Evaluation Review Technique)
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.11.1. Program Evaluation and Review Technique (PERT) Utilizes three time estimates for each activity
Optimistic, a Most Likely, m Pessimistic, b
Beta Probability Distribution Function for Each Activity
Calculates Expected Time, t
Calculates Variance, V
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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3.11.2. Estimating Activity Time
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.11.3. Probability of Finishing by A Target Completion Date Expected duration of project T is the sum of expected Activity
times on Critical Path
Variation in the Project Duration Distribution is the sum of the variations of the activity durations on the Critical Path
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.11.4. Pert Network with Expected Times and Variances
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.11.5. PERT Advantages/Disadvantages Allows “sensitivity analysis” to determine probability of
finishing the project on time
Does not account for “Near Critical Path”
Extremely complicated
Cannot account for errors in schedule logic or the ability of project manager to alter schedule logic via workarounds
Bottom Line: No better than MS Project and a lot more complicated!
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.11.6. Near-Critical Paths PERT is overly Optimistic
Paths near the Critical Path with Large Variance may become critical
Probability of Completing All Paths is the Product of Probability on each Path
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.11.7. Meeting the Target Date Actions to Shorten to Project
Move Activity on the Critical Path to a Parallel Path Add or transfer resources from activities with large slack
to critical or near-critical activities Substitute less time-consuming activities or delete those
that are not of utmost importance
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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3.11.8. Criticisms of Target Date Actions Paralleling Activities can be risky, failure of one can hurt the
other
Adding or transferring resources to speed activities increases cost and denies “resource leveling”
Substitution or Elimination can degrade end-item Performance, Requirements, Poor Quality of Work
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.11.9. Simulation of PERT Network Uses Monte Carl Methods to show the Near-Critical Path
Sensitivity
Procedure gives an Average Project Duration and Standard Deviation (Variance) which is more realistic than simple PERT
Returns Probabilities ff Other Paths Becoming Critical
Allows Historical Data
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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3.11.10. Activities and Time Estimates from Evans and Olson
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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3.11.11. Project Network from Evans and Olson
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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3.11.12. Crystal Ball Simulation Results
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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3.11.13. Criticisms of PERT Assumes Activity times can be Accurately Estimated and are
Independent
Three estimates are guesses, not necessarily better than one guess
Contractual Arrangements Influence Time Estimates
Activity Times are not Independent ( Constant Energy Surface)
Conflict of necessary Resources
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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3.11.13. Criticisms of PERT Leads to Overly Optimistic Results
Looking only at Critical Path Misleading Near-Critical Paths must be Considered
The Beta Distribution Gives Large Errors in Estimating T
Errors in T come from faulty time estimates
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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4.1. Company Profile Company Name: The Bosphorus Organisation and
Consulting Company
Founded in: 2000
Headquarter: Bremen
Employees: 75
Average Revenue: € 3.2 m
Departments: Project/Event Management&Development
Congress & Meetings Incentive & Events
Project/Event Management Consulting
Consulting Services
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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4.1. Organisation Chart
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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4.2. Definition of Project Project Name: European Student’s Days in Bremen 2010
Project Period: 17-23 July 2010
Project Goal: Between young people; Close communication and cooperation To gain new knowledge Exchange ideas
Customers/Sponsors: All Students from European Countries Municipality of Bremen Hochschule Bremen University of Applied Sciences
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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4.2. Event Program of ESD 2010
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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5.1. Work Breakdown Structure
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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5.2. Work Packages
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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5.3. Gantt Chart
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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5.4. Critical Path
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
6. Reference List
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6. Reference List Dennis Lock, Project Management, Gower Publishing; 8th
Edition, 2002 Project Management Institute (2003). A Guide to The Project
Management Body of Knowledge (3rd ed.). Project Management Institute
Martin Stevens (2002). Project Management Pathways. Association for Project Management. APM Publishing Limited, 2002
Albert Hamilton (2004). Handbook of Project Management Procedures. TTL Publishing, Ltd.
Lewis R. Ireland (2006) Project Management. McGraw-Hill Professional, 2006.
The Definitive Guide to Project Management. Nokes, Sebastian. 2nd Ed.n. London (Financial Times / Prentice Hall): 2007.
1. Definition
2. Gantt Chart MS Project
3. Networks
4. Our Company
5. Scheduling of our Project
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Akın Özkan
+49 18140307112
Burcu Uzman
+49 18140307113
Meryem Zümra Yıldız
+49 18140307114
Semih Yaraşık
+49 18140307115
Thanks for your attention!
