What is Swimlane diagram

Swimlane diagram has at least more than one entity divider and each of entity has its own process flow, thus, the swimlane diagram is good to show is good to represent process sequences for the readers as it combine one or more flowchart from different point of view (POV).

Sample of process sequence for processing natural gas into consumer LPG

For example, below are the end to end high level engineering & digital process of natural gas is processing into consumer ready LPG for cooking.

Process	Facilities
Drilling and production of natural gas - Surface/sub surface drilling to retrieve natural gas from the mother earth	Wells
Gas and oil separation. Oil will be sent to oil refinery and gas will be processed further	Surface Separator
Gas purification by sweetening and dehyrating the gas - To completely remove water, hydrogen sulfide and carbon dioxide	Gas Processing plant
natural gas liquid recovery - extract propane and butane	Cryogenic
Fractional Distilation - divide and separate hydrocarbon which can resulting in petroleum gas at 20 degrees celcius. Propane and butane are separated.	Fractionation tower
Liquefaction - Convert petroleum gas into liquid petroleum gas	LPG recovery unit
Store the LPG into gas tube - ready for end consumer usage.	LPG storage

Converting process sequence into swimlane diagram

There are at least four steps to convert and visualize process sequence into swimlane diagram

Understand the objectives & the audiences
Identify the actor/entity/system
Identify the sequences
Draw the Diagram

1.Objectives

The objective of the diagram is to show high level LPG production process for commoner (non oil and gas engineer).

2.Identify the entity

production process on any manufacturing plant or oil and gas plant will be separated based on the facilities. In this case, the raw material or gas will be flown from well then to gas processing plant until it become ready to consume liquid petroleum gas (LPG) on cyclinder tube.

3.Identify the sequences

Below are the enriched table of LPG production high level flow with process sequences.

No	Facilities	Process	Dependency
1	Well	Drilling and production of natural gas	n/a
2	Surface Separator	Gas and oil separation	1
3	Gas Processing plant	Gas purification	2
4	Cryogenic	Natural Gas Liquids recovery	3
5	Fractionation tower	Fractional distillation	4
6	LPG recovery unit	Liquefaction	5
7	LPG storage	Storage and distribution	6

4.Draw the diagram

Swimlane diagram will be drawn based on the identified process sequences above. Each facilities will be the “lane” or column and each process will be interconneted depending on the facilities and processing order.

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title: High level flow of LPG production
---
sequenceDiagram
    participant Well
    participant Surface_Separator
    participant Gas_Processing_Plant
    participant Cryogenic
    participant Fractionation_Tower
    participant LPG_Recovery_Unit
    participant LPG_Storage

    Well->>Surface_Separator: Drilling and production of natural gas
    Surface_Separator->>Gas_Processing_Plant: Gas and oil separation
    Gas_Processing_Plant->>Cryogenic: Gas purification
    Cryogenic->>Fractionation_Tower: NGL recovery (propane & butane extraction)
    Fractionation_Tower->>LPG_Recovery_Unit: Fractional distillation (propane & butane separation)
    LPG_Recovery_Unit->>LPG_Storage: Liquefaction (compression to LPG)
    LPG_Storage-->>LPG_Storage: Storage and distribution

Visualizing Process Interaction Of Natural Gas Processing Into Liquid Petroleum Gas Lpg Using Swimlane Diagram