Aalst提出了工作流有20種基本模式。
如果不知道的可參考《Workflow Patterns-2002》
工作流20種基本模式的理解（當然了，后人陸續擴展、變化，模式數量不斷變化，但萬變不離其宗，可從這些基本模式看起）
下面是我的初步分析：
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模式名稱
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模式關鍵字
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模式說明
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Basic Control Patterns
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Sequence
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Sequence
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1
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Parallel Split
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AND Split
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2
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Synchronization
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AND Join
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3
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Exclusive Choice
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XOR Split
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4
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Simple Merge
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XOR Join
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5
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ADVANCED BRANCHING AND SYNCHRONIZATION PATTERNS
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Multiple Choice
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OR Split
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6
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Synchronizing Merge
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AND Join
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7
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Multi-merge
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OR Join(+Multi)
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8，
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Discriminator
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OR Join(+Reset/Ignore)
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9
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N-out-of-M-join
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OR Join(+Multi M)
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9a，N分支，M聚合即可
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STRUCTURAL PATTERNS
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Arbitrary Cycles[自由循環]
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XOR Split
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10
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Implicit Termination
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Multi(OR/AND) Split End
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11
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PATTERNS INVOLVING MULTIPLE INSTANCES
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MI without synchronization
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Runtime independent thread by condition
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12，在運行期創建獨立實例（線程、程序等）
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MI with a priori known design time knowledge
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Design time priori Instance
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13，設計期多實例，且需全部完成
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MI with a priori known runtime knowledge
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Runtime multi Instance by condition/free
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14，運行期可基于條件創建多實例
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MI with no a priori runtime knowledge
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Runtime multi Instance free by people
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15，運行期可手工隨意創建多實例
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STATE-BASED PATTERNS
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Deferred Choice
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XOR Split(By choice)
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16，“推著走”流程，或基于既定條件分支
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Interleaved Parallel Routing
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OR Split + OR Join, Parallel
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17，多分支聚合，分支執行順序由運行期確定
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Milestone
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Wait by Milestone
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18，在“里程碑”節點等待
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CANCELLATION PATTERNS
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Cancel Activity
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Cancel in specified Activity
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19，在指定的活動取消
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Cancel Case
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Cancel Anywhere/Anytime
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20，任意時候可取消
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可以看到，其實很多是類似的，這為下一步的工作流引擎需求、設計打下基礎。
拋磚引玉，供大家參考。