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(Re)designing workflows Tips and tricks.

Wil van der Aalst

Eindhoven University of TechnologyFaculty of Technology ManagementDepartment of Information and TechnologyP.O. Box 513 5600 MB EindhovenThe Netherlandsw.m.p.v.d.aalst@tm.tue.nl

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Designing a workflow

What?

How?

By whom?

begin

realization

objectives

tasks andprocesses

resources andscheduling

analyze

analyze

analyze

text

resource classificationallocation rules

process definition

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Guidelines

• Start with the identification of a case.What is the case?

– A case is often initiated by a customer (internal or external!)

– The process adds value to a case.

– A case has a life-cycle with begin and end.

– A case cannot be divided, but the work can.

• Determine the scope of the process as soon as possible.

• Determine the goal of a process (added value).

• Ignore the existence of resources during the design of a process.

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Guidelines (2)

• Workflow modeling is an iterative process– don't be afraid to make mistakes !!

– tasks are split and joined during the process

– use hierarchy: divide and conquer

• During the process a task should become a Logical Unit of Work (LUW)

– atomic: commit or rollback

– a task is executed by the same person, at the same time, at the same place

– avoid setup times (not too small)

– avoid large chucks (commit work should be limited)

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Extracting information from an existing process.

• Follow (paper) documents.

• Identify communication between people, teams and departments.

• Identify regular communication patterns (dialog/protocol).

A B Crequest

commandinformation

request

information

responsemessagesequence

chart

A

B

C D

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Reengineering workflows• BPR: fundamental, radical, dramatic, process.

• Ignore existing processes and organization.

• Symptoms of a sick process:– too many cases (in-process-inventory)

– (throughput time / service time)-ratio is too high

– service level (% in time) is too low

• Key performance indicators:

– throughput time, waiting time, service level

– occupation rate, number of cases, ...

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Guidelines for BPR

• Check the necessity of each task.

• Appoint a process manager.

• Appoint case managers.

• (Re)consider the size of each task.

• (Re)consider the trade-off between a generic process and multiple versions of the same process.

• (Re)consider the trade-off between a generic task and multiple specialized tasks.

• Try to introduce more parallelism.

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Guidelines for BPR (2)

• Investigate new opportunities as a result of modern technology.

• Optimize communication structure.

• Do not automate paper workflows!

• An electronic document is everywhere and nowhere.

• Use resources as if they are in the same room.

• Use a resource for what it is good at.

• Maintain as much flexibility as possible for the future.

• Avoid setup times by clustering tasks.

• Avoid setups and exploit routine by clustering cases.

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Design criteria

A process design is evaluated on the basis of four

key issues:

• time

• quality

• costs

• flexibility

Often there is a trade-off!

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Design criterion 1: Time

• Throughput time is composed of:

– service time (including set-up)

– transport time (can often be reduced to 0)

– waiting time

» sharing of resources (limited capacity)

» external communication (trigger time)

• There are several ways to evaluate throughput/waiting time:

– average

– variance

– service level

– ability to meet due dates

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Design criterion 2: Quality

• External: satisfaction of the customer

– Product: product meets specification/expectation.

– Process: the way the product is delivered (service level)

• Internal: conditions of work

– challenging

– varying

– controlling

There is often a positive correlation between external and

internal quality.

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Design criterion 3: Costs

• Type of costs

– fixed or variable,

– human, system (hardware/software), or external,

– processing, management, or support.

Note the trade-off between human/system-related costs.

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Design criterion 4: Flexibility

• The ability to react to changes.

• Flexibility of

– resources (ability to execute many tasks/new tasks)

– process (ability to handle various cases and changing workloads)

– management (ability to change rules/allocation)

– organization (ability to change the structure and responsiveness to wishes of the market and business partners)

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Trade-off

Costs

Quality

Time

Flexibility

(T+/-,Q+/-,C+/-,F+/-)

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(1) Check the necessity of each task

• Every "check task" may be skipped: a trade-off between the costs of the check and the costs of not doing the check.

A B

check

A B

A B

check

auto-select

(T+,Q-,C+/-)

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(2) Appoint process/case managers• A process manager monitors a process to see whether

there are bottlenecks, capacity problems and delayed cases. Management instruments: motivating the people involved in the process and control parameters.

• Case managers are assigned to a case. They are responsible and execute as many tasks as possible for the case. Benefits:

– commitment

– reduction of setup time

– one contact person

(Q+)

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(3) (Re)consider the size of each task

Pros: less work to commit, allows for specialization.Cons: setup time, fragmentation, less commitment.

Pros: setup reduction, no fragmentation, more commitment.Cons: more work to commit, one person needs to be qualified for both parts.

Also a trade-off between the complexity of the process

and the complexity of a task. (T+,F-)

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(4) Trade-off: one generic process or multiple versions

A

B

A

B

A\BA B

B\A

Issues: simplicity, efficiency, controllability, maintainability, ...(F+/-)

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(5) Trade-off: one generic task or multiple specialized tasks

• Similar considerations.

• Specialization may lead to:

– the possibility to improve the allocation of resources

– more support when executing the task

– less flexibility

– a more complex process

– monotonicity

(T+,F-)

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(6) Introduce as much parallelism as possible• More parallelism leads to improved performance:

reduction of waiting times and better use of capacity.

• Two types of parallelism: semi and real parallelism.

• IT infrastructures which allow for the sharing of data and work enable parallelism.

A B

A

B (T++)

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(7) Investigate opportunities of IT• DBMS: sharing of data

– An electronic document is everywhere and nowhere!

• Network technology:– communication: e-mail, WWW, ...

– distribution of information: transportation of data is fast, cheap and convenient

• Automation of task or automated support of tasks

• Examples:– parallel (sharing of data)

– customer involvement (sending forms via the WWW)

– form synchronous to asynchronous communication

– risk analysis based on historical data Do

not a

utom

ate

pape

r w

orkf

low

s!

(T+,Q+/-,C+/-,F-)

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(8) Improve the allocation of resources• Use resources as if they are in one room: avoid (at any time!)

the situation where one group of people is overloaded and another (similar) group is waiting for work.

(T+,Q-)

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• Let people do work that the are good at. However, avoid inflexibility as a result of specialization!

• Stimulate resources to build routine.

• When allocating work to resources, consider the flexibility in the near future.

• Avoid setups as much as possible. There are two kinds of setups: (1) case setups and (2) task setups.

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(9) Improve communication structure• Reduce the number of messages to be exchanged

between the process and the environment.

• Try to automate the handling of messages (send/receive).

• Avoid communication errors (EDI,WWW).

• If possible, use asynchronous instead of synchronous communication.

(T+,Q+,C+/-,F-)

A B Crequest

commandinformation

requestinformation

response

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(10) Order tasks based on cost/effect

• Consider the class of “knock-out processes”, e.g., hiring people, handling claims, etc.

• Postphone expensive tasks until the end.

• Execute highly selective tasks first.

• In other words: order the tasks using the ratio “costs/effect”.

(T+,C-)

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Case