(Re)designing workflows Tips and tricks.

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(Re)designing workflows Tips and tricks.
Wil van der Aalst

• Eindhoven University of Technology
• Faculty of Technology Management
• Department of Information and Technology
• P.O. Box 513
• 5600 MB Eindhoven
• The Netherlands
• w.m.p.v.d.aalst_at_tm.tue.nl

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Designing a workflow
begin
analyze
What?
analyze
objectives
How?
analyze
text
tasks and processes
By whom?
process definition
resources and scheduling
realization
resource classification allocation rules
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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.

C
A
D
B

• Identify regular communication patterns
  (dialog/protocol).

A
B
C
request
command
information
information
message sequence chart
request
response
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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
Time
Flexibility
Quality
(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.

(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\B
A Ç 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.

(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 automate paper workflows!
(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-)
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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