You may think that the project life cycle and the product life cycle are similar, but they are not. As a project manager, you should know the difference between these two concepts to align your business and project objectives.
Since a project produces a product and then ends and the product stays longer, the product life cycle is bigger than the project life cycle.
On the PMP exam, you may see a few questions on this topic, so understand it well.
Project Life Cycle
A project life cycle is the sequence of phases a project goes through, from initiation to closure. Projects are undertaken to produce a product, service, or result, and after delivering the output, the project ceases to exist, and the project life cycle ends.
A project life cycle has many phases, and each phase consists of activities from these process groups: initiation, planning, executing, monitoring and controlling, and closing. The phases are generally sequential and can overlap.
In the initiation phase, you develop the project charter and identify stakeholders.
The project management plan will be developed during the planning phase, and you will build the actual product in the execution phase.
Monitoring and controlling activities happen throughout the project, although these processes can overlap or repeat.
In closing, you hand over the product to the client and close the project.
Project life cycles are not necessarily a part of the product life cycle. If the project’s output is a service or result, it will not be a part of the product life cycle.
The PMBOK Guide defines the project life cycles in four phases:
- Starting the project
- Organizing and preparing
- Carrying out the project work
- Closing the project
The following are some characteristics of a project life cycle:
- Risks are higher when the project starts and decrease as the project progresses.
- Staff requirements are low at the beginning of the project, maximum during the execution, and afterward, may decrease.
- The cost of changes is lowest at the beginning of the project, and it starts increasing as the project moves further.
- Stakeholder influence is higher at the beginning of the project, and it starts decreasing as the project moves further.
- Most of the funds and time are spent during the execution phase.
Example
Suppose you have a project to build a new motorcycle.
First, you identify the stakeholders and collect the requirements. Once the requirements are collected, you will develop a plan to build the motorcycle.
Then, you start the real work of building the motorcycle.
Finally, you will hand over this product to your client, and the project will be closed.
Product Life Cycle
The product life cycle describes the stages a product passes through, from conception to retirement.
The product life cycle stages are development, introduction, growth, maturity, and retirement. These phases are sequential and do not overlap. The project life cycle can be a part of one or more phases in the product life cycle.
In the development stage, you will generate the idea and create the product.
The introduction stage is for marketing the product and starting to sell the product to customers.
In the growth stage, the sales increase.
In the maturity stage, the product is accepted, and sales are at their peak.
The last stage is the retirement stage. At this level, you will try to sell out all of your inventory and move on to the next product. This stage happens due to technical advancement, or your product is not selling enough to support its production cost.
Not all products reach the final stage; some are discarded, and others never expire.
Product life cycle phases have no duration limit; one phase can be longer than the others. For example, the Toyota Corolla and Camry are old products and are still in the growth or maturity stage, and I do not see them retiring any time soon.
A product life cycle can have many project life cycles. For example, the first project life cycle can be the development of the project, and the other is adding a function to the product.
In most cases, the project life cycle is a subset of the product life cycle because the product life cycle continues even after the project is completed.
Example
Let’s consider the product life cycle for a new motorcycle that your company wants to launch.
The first step is idea generation. This includes a feasibility study, market research, and a business plan. Then, you initiate a project to build this bike.
Your project is complete once the motorcycle is ready and the project life cycle ends. However, the product life cycle continues. Now, the next phase of the product life cycle begins: selling and marketing the motorcycle.
You will provide after-sale support after selling, and the retirement phase begins.
The retirement phase may include selling motorcycles at a discounted price.
During the product life cycle, if you add new functions to the product, you will create a new project for this process: for example, increasing the engine capacity of the motorcycle to support faster pickup.
The Differences Between the Project and Product Life Cycle
The following are a few differences between the project life cycle and the product life cycle:
- A product life cycle can have single or multiple projects.
- The product life cycle is longer than the project life cycle.
- The project life cycle has a definite end, while the product life cycle may not.
- The map for the product life cycle is conceptual and depends on market conditions, while projects have predictive and well-defined roadmaps.
- The product life cycle phases do not overlap, while the project phases may overlap.
- Phases generally occur only once in the product life cycle, while phases may repeat in the project life cycle.
- Phases are sequential in the product life cycle, while phases may or may not be sequential in the project life cycle.
Summary
The project life cycle is a part of the product life cycle. The project life cycle is usually a subset of the product life cycle. The product life cycle starts from the inception of the idea and ends when the product is retired. The organization’s business model depends on the product cycle. A product life cycle includes the entire life of the product including updates and upgrades, however, products are upgraded with the help of a project.
Please share your role in the project or product life cycle in the comments section.
I am Mohammad Fahad Usmani, B.E. PMP, PMI-RMP. I have been blogging on project management topics since 2011. To date, thousands of professionals have passed the PMP exam using my resources.
So what is a main success factor for a project
why does the project manager need to understand both?
A project manager needs to understand a lot more than these two.
The 5 process groups form the project management life cycle. Project life cycle is a series of phases, each of which can repeat or overlap the life cycle starting from inception feasibility, design, engineering, development, construction / manufacturing, commissioning to handover to operations or client. Product life cycle is a series of phases from introduction, growth, maturity to decline. Correct and agree?
You are right Jo.
Please correct me if I am wrong, my understanding is most money spent during execution and most time spent during planning.
Most of the funding and time is spend during the execution phase.
Thank you for the article.
I am working on an assessment of the Project Life Cycle. After some research I am confused, many resources suggest the Project Life Cycle has 5 phases (Initiate, Plan, Execute, Control and Close) – others define it as 4 phases (not including Control) and worded slightly different. Thoughts?
This is what I have explained in this blog post. What is your specific doubt?
Thanks Fahad, this is one of my favourite blog.
After reading this blog, now I got a good understanding between Project life cycle and Product life cycle.
Could you please share me the difference between Continous process improvement and Process improvement plan.
Thanks for your Help in advance…!
I have noted it, and soon try to write a blog post on this topic.
Dear Fahad,
Thanks for posting the article.
But I have one query, please clarify.
What I understand is Initiation, Planning, Executing , Monitoring and control and Closing are Project management cycle phases and not project life cycle phases.
Project life cycle phases (may be as per blog Product life cycle phases) are totally depends on type of industry and can not generalised.
Mean to say project life cycle phases are one fit one.
The PMBOK Guide defines the project life cycles in four phases:
1) Starting the project
2) Organizing and preparing
3) Carrying out the project work, and
4) Closing the project
It is same for all kinds of project regardless of industry.
Hi Fahad,
Looking for sample practice questions w.r.t. 8 new tasks added in 2016.
Any help is highly appreciated.
Regards,
Rafiq
Hello Rafiq,
I don’t have any set of questions specific to these newly added tasks and I doubt that you will find it elsewhere.
Assalam-o-Alaikum
Why Iterative life cycle and Incremental life cycle have same definition in PMBOK 5 Pg. 543 and 544
Thanks
WaSalaam,
Read the last sentence which clears the difference between the two.
Dear Fahad,
Reading your blogs is an education in itself. You bring the complex explanations, translated to layman’s language and make these concepts edible. Always a pleasure to read your posts.
With warm regards
K.N.Jayanth Krishnamoorthy
Thank you Mr Krishnamoorthy for your comment.
Dear Fahad As per the PMBOK guide 5 edition Pg 39, is it correct to say the following:
Project life cycle has 4 phases:
1- starting the project (ie. initiation group)
2- Organizing and preparing (ie. Planning process group)
3- Carrying out project work (ie. Executing, Monitor &Control process group)
4- Closing (ie. Close process group).
On pg 38 PMBOK guide, it says that the phases of the project life cycle are generally sequential but the blog says that the phases can overlap.
Also PMBOK guide says that the project life cycle should not be confused with the process groups. Please guide. thanks
Let’s say you have a big project and you have divided into phases. You have started working on phase-I, you do the planning, executing, controlling and then closing. This phase is completed and deliverable is handed over to the client. Now you started the phase-II and you again go through the planning phase, executing phase, etc. So you can say that phases can overlap.
The 5 process groups (initiation, planning, execution , monitor&control, closing) are NOT phases, like stated by PMBOK and quoted by Mohammed. Project lifecycle are what PMBOK states at pag. 38 and also reported by you: but process groups are not phases, so they cannot be a project lifecycle. That is what is written in the PMBOK, please stick on that. . Phases, for example in a usual automotive project lifecycle model could be: project preparation, concept detail, product&process development, production preparation, ramp up&close out. They are not the same as process groups, even if to some extent that can look like from the wording. Same process groups may happen several time at different project phases (for example, monitor&control process gorup), but process gorups are not phases…that is hwat is writte. And that is what you get if you really understand what is the difference between processes needed to manage a project vs. processes needed to develop a product or a service.
Corrected.
Dear Fahad,
Thanks for your pure clarification , you answer some questions that I try to understand ,
Now diffrence between project and product completely clear
Thanks again
You are welcome Nemat.
Dear Fahad,
PMBOK says “The Process Groups are not project life cycle phases”. But what I understood from your blog that process gropus are nothing but project life cycle phases. Please clarify.
As per the PMBOK Guide fifth edition 2.4 page 38: A project life cycle is the series of phases that a project passes through from its initiation to its closure.