Product Goal provides a high level view about the destiny of the product and defines the end goal for the product.
It broadly answers the questions of
- Why are we doing it? – The reason why we are building
- What does it solve? – Need for the Product
- Who are we building it for? – Target Customers
- What are we building? What is our MVP?
- When are we looking to deliver? – Timeframes
- How much would be the initial investment for product introduction?
- How much would end customer pay?
- Who are our competitors? What are our differentiators with respect to our competitors?
When do we write the Goal?
The vision is usually written down after confirmation from market research – from talking to customers and working with all stakeholders.
Why would anyone write a Goal?
The Product Goal helps the team to stay focused on the end destination and not deviate into different routes. The Product Goal should drive any product. There are instances where the teams may struggle in the course of the implementation but the goal kept reminding the team of the final destination and kept the team moving towards the goal.
When is the Goal Achieved?
We do not achieve the product goal overnight. The Goal is generally achieved Incrementally and Iteratively (in the new way). That means we develop small releaseable products (Incremental) which help us to achieve some parts of the goal. Then based on the feedback received (iterative) we end up doing changes to our product and keep creating new Increments. Slowly and steadily, what we intended to achieve, may be achieved. At that time we can say the product Goal is achieved. In Agile way of working, its not about developing all scope. We give upmost importance to “Customer Value” rather than trying to develop everything that we decided to do at the time of envisioning the product. The feedback process helps us to achieve our Goal better. Traditionally, it was believed that Goal should be achieved big-bang and everything that needs to be done has to be done to achieve the Goal. So there are two views on achievement of Goal – the traditional way and the new way. In the modern world, it is almost impossible to achieve the goal as per the traditional thinking. Most people therefore are adopting the incremental-iterative way which delivers goal in pieces (by delivering value continuously). Broadly Goal achievement (traditional and new way) may follow the curve as shown below. 
Why is Goal critical in Product Delivery?
The product goal is especially critical in an agile environment as decision making is fluid and scope is changed over the course of the product delivery to fit changing environments and new discoveries. The Goal drives every day decision making and makes every day challenges more meaningful. All the sprint goals should add up to the goal and take the team towards the goal. When there is no vision, the goals are meaningless and the planning can take many a detours. The Product Goal leads the creation of the Product Roadmap which drives the release plan that drives the Sprint plan and which should drive the daily tasks!
Desirable Qualities of Goal
The goal should communicate the essence of the future product in a concise manner and describe a shared goal that provides direction but is broad enough to facilitate creativity. Qualities of Goal are described by Roman Pichler very well in his book “Agile Product Management with Scrum”. Roman Pichler describes the following characteristics of Goal:
- Shared and Unifying : Everyone involved in the development effort should buy into the vision: Scrum team, management, customers, users, and other stakeholders.
- Broad and Engaging : The product goal should describe a broad and engaging goal: a goal that guides the development efforts but leaves enough room for creativity, a goal that engages and inspires people.
- Short and Sweet : When it comes to the product goal, less is more. The goal should be brief and concise. It should contain only information critical to the success of the product.
Conclusion
Product Goal is a “End Goal” for any Product. This “End Goal” helps the team to remain focused towards achievement of the value for the customer.