Write out the problem statement. Include information on what you are to solve, and consider why you need to solve the problem.

Make sure you are solving the real problem as opposed to the perceived problem. Use techniques such as "Finding out Where the Problem Came From," "The Duncker Diagram," "The Explore Phase," etc. to check to see that you define and solve the real problem. Recast the problem statement if necessary.

Draw and label a sketch. Define and name all variables and/or symbols. Show numerical values of variables if known.

Identify and name Relevent principles, theories and equations Systems and subsytems Dependent and independent variables Knowns and unknowns Inputs and outputs Necessary (missing) information

List assumptions and approximations involved in solving the problem. Question the assumptions and then state which ones are the most reasonable for your purposes.

Check to see if the problem is either under-specified or over-specified. If it is under-specified, figure out how to find the missing information. If over-specified, identify the extra information that isn't needed.

Relate problem to a similar problem or experience (compare to an example problem in lecture or in the book).

Use an algorithm (e.g. reaction engineering)   Mole Balance Rate Laws Kinetic Transport Stoichiometry Gas or liquid Pressure drop Combine Energy Balance Evaluate

Develop/derive/integrate and/or manipulate an equation or equations from which the desired variable can be determined.

Substitute numerical values and calculate the desired variable. Check your units at each step in the solution to find possible errors.

Examine and evaluate the answer to see it makes sense. Is it reasonable, considering the problem statement? Does it consider safety and ethical issues?

See how this algorithm can be applied to Examples in Chemical Reaction Engineering.