What is the difference between the project life cycle and the product life cycle?
This is a question I have often been asked by many visitors to my website, and some of them have requested me to write a blog post on it.
So, here is the blog post on the project and product life cycle.
To many people these terms may look similar to each other; however they are different, and as a project manager you should be aware of these terms and the difference between them.
Okay, let’s discuss it in detail.
Project Life Cycle
Most of the time projects are undertaken to produce a product, and once the product is delivered the project ceases to exist.
It does not matter what kind of project you are managing; the project management fundamentals are same in all fields. A project life cycle can have many phases and each phase can consists of any activities from these process groups: initiation, planning, executing, monitoring & controlling, and closing. The phases are generally sequential and can overlap.
In the planning, the project management plan will be developed which will help you execute your project.
In the execution, you do the real work. Here the actual project work is carried out and the product is built.
Monitoring and controlling happens throughout the project to check if you are deviating from the plan or if any mistakes are happening.
In the closing, you hand over the project to the client and close the project.
Monitoring and controlling activities happen throughout the project, although these processes can overlap or repeat.
Please note that it is not always necessary that a project be a part of the product life cycle. A project’s output can be any service or result, and in this case 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, and
- Closing the project
The following are a few characteristics of a project life cycle:
- Risks are higher when the project starts and they decrease as the project moves further.
- Staff requirements are low at the beginning of the project and are at a maximum during the execution phase, and then they 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 money and time are spent while carrying out the project work.
Suppose you have a project to build a new motorcycle.
To build the motorcycle, first of all you identify the stakeholders and collect the requirements. Once the requirements are identified, you will develop the project management plan to build the motorcycle and develop the schedule.
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
Now we come to the product life cycle.
The product life cycle starts from the inception of the idea to the point when the product is retired. The stages of the product life cycle are: development, introduction, growth, maturity, and retirement. Usually 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 to create the product and the product is created.
In the introduction stage, you will start marketing the product and begin selling the product to customers.
In the growth phase, the sales increase.
In the maturity stage, the product is accepted widely and sales are at their peak.
Last 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 because your product is not selling enough to support its production cost.
Please note that there is no time limitation for any phase. For some products these phases are small and for other phases duration is too high. For example, Toyota Corolla and Camry are very old products and are still in the growth/maturity stage, and I don’t see them coming under the retirement stage in the near future.
Moreover, a product life cycle can have many project life cycles. For example, the first project life cycle can include the development of the project, and then other project life cycle can be the addition of another function to the product.
You can say that, generally, the project life cycle is a subset of the product life cycle because the product life cycle continues to exist even after the project is completed.
Let’s consider the product life cycle for a new motorcycle that your company may want to build and sell in the market.
The first step of this product life cycle can be the idea generation. This may include a feasibility study, market research and the business plan. When this phase is complete you will initiate a project to build this bike.
Once the motorcycle is built, the project will be complete and the next phase of your product life cycle begins, which is marketing and selling motorcycles to customers.
After selling you may need to provide after sale support, and then the retirement phase occurs.
The retirement phase may include selling motorcycles at a discounted price.
Please note that if during the product life cycle you add any new function to the product, you will create a new project to do so, for example, increasing the engine capacity of the motorcycle to support faster pickup.
The Difference between the Project and Product Life Cycle
The following are a few differences between the project life cycle and product life cycle:
- 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.
- A product life cycle can have single or multiple projects.
- The map for the product life cycle is somewhat conceptual and depends on the market condition; on the other hand projects have predictive and clearly defined roadmaps.
- The product life cycle phases do not overlap while the project phases may overlap.
- In the product life cycle, phases generally occurs only once, while in the project life cycle phases may repeat.
- In the product life cycle phases are sequential, while in project life cycle phases may or may not be sequential.
Although the project life cycle and the product life cycle are different, they are related to each other in most cases. The project life cycle can be a part of one or more product life cycle phases. In the project life cycle you develop or enhance the product while the product life cycle includes everything related to the product. The product life cycle starts from the moment when you think of it until the product is retired, which obviously includes the project life cycle.
Here is where this blog post on project and product life cycle ends. If you have something to share, you can do so through the comments section.