In your plan you should have;
Assessment Criteria
0
The student does not reach a standard described by any of the descriptors
given below.
1-2
The student produces a plan that contains some details of the steps and/or
the resources required.
3-4
The student produces a plan that contains a number of logical steps that
include resources and time. The student makes some attempt to evaluate
the plan.
5-6
The student produces a plan that contains a number of detailed, logical
steps that describe the use of resources and time. The student critically
evaluates the plan and justifies any modifications to the design.
Sample students' Plan:
http://myp-tech.wikispaces.com/file/view/tech_05_C_en.pdf
You can use tomsplanner
http://www.tomsplanner.com/