Timeline of Child Milestones, Development Stages, & Signs Check your child's stage of child development and learn the signs of developmental delays. Is Your Baby on Track? Check WebMD's timeline of childhood milestones and learn the signs ofAuthor: Sherry Rauh Developing a Timeline | The Good Project Developing a Timeline. In any project, developing a timeline is important and essential. It is useful in terms of organizing the work that lies ahead, but it is also helpful to hold all individuals and parties (in this case collaborators) accountable for completing work when it needs to get done.