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IELTS Writing
Task 1 Essentials
All about process diagrams

All about process diagrams


There's nothing particularly special about writing a report for a process diagram. You should be able to write complete sentences to describe a process. This often requires appropriate topic vocabulary. To meet the task requirements, you should follow these instructions.

Note: According to an expert at IDP, natural processes such as the life cycle of a butterfly are no longer (or very rarely) used. This lesson is about manufacturing processes.

Update (2022): There are been natural processes used in the test recently. Here's a recent question: Sand dune formation

  1. Use the simple present tense. Sometimes the present perfect can be used.
  2. Use passive voice. Sometimes the active voice can be used.
  3. Use "steps" language: first, then, next etc.
  4. Use pronouns and determiners: it, they, this...
  5. Use relative clauses (which/that).
  6. Use indefinite and definite articles properly. (As a general rule, when something in the process is mentioned for the first time, use "a/an". When it is mentioned again, use "the".)
  7. Make good use of the given labels and descriptions on the diagram.

To make sure the description is well extended

  1. Do not miss the small details in the illustration
  2. Consider the relationship between steps (e.g. one step makes the next easier)
  3. Identify the purpose of each step and state it (unless it is too obvious)

Structure and methods

4-paragraph structure

A process diagram report has the same structure as the other types: an introductory paragraph, an overview, two details paragraphs.

Introductory paragraph

For the introduction, NVSR can be used, and it's even much easier to apply since most parts are basically the same.

The diagram shows the stages and equipment that are involved in the process of producing ethanol fuel from corn.


As for the overview, because a process diagram is fundamentally different from charts and graphs, CLEAR cannot be used. Instead, we use GRAMS.

  • Genesis and Result: the beginning and the outcome of the process
  • Attribute: a main characteristic of the process (e.g. modern, traditional, labor-intensive, simple, complicated, requiring special machines, (largely) mechanical etc.)
  • Max time: the total amount of time require to complete the process (often seen in a natural cycle)
  • Sum of stages, steps or parts: the total number of stages or steps in a process or the total number of parts in a machine or structure

A stage is a set of related steps.


Make sure you include the sum of stages, steps or parts in the overview, as the band descriptors (Band 7) states that the report must present a clear overview of main trends, differences or stages.

A process showing the process of producing bricks

Here are some overview features for the diagram above.

  • G & R: digging clay and distribution
  • A: the baking stage requires a range of temperatures
  • M: N/A
  • S: 7 steps in total

And here two examples of overviews that use the features identified above.

It is clear that the process consists of 7 consecutive steps. It starts with collecting clay and ends at finished bricks, ready for delivery.

It is clear that the process consists of 10 consecutive steps. It requires a certain range of temperatures so that the bricks are properly baked.


What if I can't count the steps?

  • Read the steps carefully and try to group the related ones together. Each of these groups is a main stage. Usually, you should group the steps that result in a significant change in the form of the product.

  • Note that some diagrams do show you the main stages that comprise individual steps, like the one below.

A process showing the process of producing carbonated drinks

Another example of stages in the overview.

A process showing the process of producing fish pie

Overall, this process comprises two three main stages: the preparation of potatoes, the processing of fresh salmon, and the assembling.

And one more example.

A process showing the process of producing clothes from plastic bottles

Overall, this is a largely mechanical process comprising three main stages: the collecting and sorting of bottles, their processing, which turns them into yarn, and finally the weaving stage.

Details paragraphs

Generally speaking, we split the process into two halves. Sometimes it's quite obvious where you should split it (e.g. when the material is transported to another factory for further processing), other times it's not. There're two points to keep in mind:

  1. The two paragraphs should ideally have similar amounts of information.
  2. Avoid spliting where two steps are closely connected to each other.
  3. If you've identified the main stages, you can the details paragraphs based on them.
    • At the first stage of the process,…
    • The second stage involves [number] steps.
    • Note: If there are more than 2 stages, group them appropriately. e.g. At the first two stages of the process,… During the final stage,…

Usually the problem is that you may produce an underlength answer. To deal with this, try to add extra information whenever you can, by asking questions, e.g. How are the bottles sorted?, Why is the fruit washed?

Useful vocabulary


  • The figure illustrates the process used to...
  • The figure illustrates the way in which...
  • The figure illustrates the stages and equipment that are involved in the process of…


  • The process can be outlined in [number] steps/stages.
  • The process starts with… and ends at…
  • Overall, there are… steps/stages in the process, from…, through…, to…
  • This process comprises [number] main stages:…
  • Note: Notice the difference between "consist" and "comprise" in usage.
    • consist of sth
      • The process consists of…
    • comprise sth (NOT comprise of sth)
      • The process comprises…
    • be comprised of sth
      • The process is comprised of…

Details paragraphs

  • First (of all)
  • Then
  • Next
  • After that
  • After
  • At the first/second... stage (of the process)
  • At the start of the process
  • In the first step
  • The first/second... stage in the process is that...
  • Once sth have/has been V3,…
  • The resulting + noun
  • Following this
  • Subsequently
  • This stage is followed by
  • Alternatively
  • Concurrently
  • At the same time

Make sure that you vary the way you use linking words.

More complex transitions

  • after being V3
  • at this point
  • at which point
  • after which
  • where
  • in the next step (can be used at the beginning of the second details paragraph)
  • subsequently (better used in the middle of a sentence)
  • finally
  • this noun
  • , thereby gerund (usually used in the end)

When there's a specific machine used, but you're not sure what it does, you can "cheat" with the phrase "be passed into/through (machine's name)". Otherwise, take advantage of the given words, as stated in the Approach section.

Other vocabulary

  • sold at retail establishment
  • sold to the public
    • for sale to the public
  • the delivery of … to retail outlets
  • manually (when something is done by hand)
  • melt → molten
  • a mechanical claw
  • apple/cherry/pear orchard (fruit or nut trees, not citrus)
  • orange/lemon/palm/banana/coconut/olive/coffee grove
  • cannery
  • warehouse
  • spawn (v/ noncount n)
    • spawning grounds

Life cycles

  • The diagram gives information about the various stages in the life of the..
  • Overall, the full lifecycle of… takes…, from…, through…, to…
  • The lifecycle of the… begins when…
  • In the next stage,…