When a project is analyzed and failed, users usually get confused and have no idea on how to troubleshoot the error behind the warning/error messages. 

Therefore, this guideline will help users to have better understanding on why the analysis failed and how to correct it to ensure a successful analysis to meet the satisfactory design.  

Flowchart below can be use as reference when the design analysis failed:

Troubleshooting Analysis Failure #

Unable to find suitable IL configuration based on the constraints #

Try to unfix the IL  and/or ensure drain size fulfill site condition, and/or make sure that the drains/pipes are going from higher ground to lower ground, or use cascading drains if applicable

Suggested Solutions for Issue 1

i. Check for any outrageous drain size 

ii. Review ILs; unfixed/adjust invert level

Steps to applied: 

• Go to Drain > Spread Input > Dimension > Change drain size 
• Analyse > analysis successful > OK 
• Review outputs > Export results (if require)

Other alternative is to change the maximum depth in Parameter Settings 

• Go to Options > Project Parameters > Drainage
• Design  > General > Max Depth (you probably need to increase the value, given all the constraints)

Fixed drain height is larger than fixed depth of connected node  #

Suggested Solutions for Issue 2

i. Review ILs; unfixed/adjust invert level 

ii. Proposed smaller drain size and/or do not fix drain size

Steps to applied:

• Go to Drain > Spread Input > Invert Level, change iterate ‘NO’ to ‘YES’ 
• Analyse > analysis successful > OK > export results 

OR 

• Go to Drain > Spread Input > Dimension >  use smaller drain size and/or do not fix the drain size 
• Analyse > analysis successful > OK > export results

Peak Flow Higher Than Capacity #

Suggested Solutions for Issue 3

i. Review fixed drain size and enlarge dimension  

ii. Set iterate drain dimension from ‘NO’ to ‘YES’

Steps to applied: 

• Go to output > excel report > check remark and identify which drain have less capacity than peak flow
• Go to input > drain > spread input > dimension > enlarge drain dimension 
• Analyse > analysis successful > OK >  export results

OR 

• Go to output > excel report > check remark and identify which drain have less capacity than peak flow
• Go to input > drain > spread input > dimension > iterate from ‘NO’ to ‘YES’ 
• Analyse > analysis successful > OK >  export results

Gradient is out of range #

Suggested Solutions for Issue 4

i. Check gradient iteration 

ii. Check minimum/maximum gradient set in parameter (drain type basis)

Steps to applied:

• Go to drain > spread input > gradient > change iterate ‘NO’ to ‘YES” 
• Analyse > Analysis successful > Review Outputs > export results 

OR 

• Go to ‘Project Parameters’ > Drainage > Drain types > change minimum and maximum gradient (change per drain type basis) 
• Analyse > Analysis successful > Review Outputs > export results

Velocity out of range #

Suggested Solutions for Issue 5

i. Check gradient  iteration 

ii. Check minimum and maximum velocity in parameter

Steps to applied:

• Go to drain > spread input > gradient > proposed a suitable gradient value  or change iterate from ‘NO’ to ‘YES’ 
• Analyse > Analysis successful > Review Outputs > export results 

Note: 

• This suggestion will depend on situation  whether the velocity is less than the minimum velocity or more than maximum velocity set in the parameter 
• If the velocity is less than the allowable minimum velocity, user  may propose a steeper gradient and/or propose a smaller drain size 
• As for velocity more than the maximum allowable velocity, user may propose a gentle gradient and/or propose a bigger drain size 
• By applying suggestion above, user will be required to analyse the project and see how the velocity changes and make appropriate changes to achieve satisfactory design 

OR 

• Go to ‘Project Parameters’ > Drainage > Design > change minimum and maximum velocity to suit the project needs 
• Analyse > Analysis successful > Review Outputs > export results

Some drains ILs are set higher than permissible level in relative to the ground #

Suggested Solutions for Issue 6

i. Review ILs; unfixed/adjust invert level or change ‘Min Cover of Culvert,m’ at parameter setting

Steps applied: 

• Go to drain > spread input > check fixed invert level > try to unfix; change iterate ‘NO’ to ‘YES’ 
• Analyse > analysis successful > review outputs > export results

OR 

• Go to Project Parameters > Drainage > Design > change ‘Min Cover of Culvert,m’ (if necessary)

What to do if you have no idea how to troubleshoot, there are just too many failures and errors! #

1. Check the ground level, make sure that they are reasonable. You can also check the Long. section to detect the abnormality of the Ground Level. i.e: all nodes are 0, but the final node is 100m, this is definitely not reasonable
2. Set iterate dimension=NO for all drain/pipe dimensions, use your hand picked dimension first to analyze, and see what do you get from there
3. Try not to constraint the IL too much. Try to set only the starting node invert level and other very essential ILs, and let the computer figure out the rest. 
4. If you really want to control how the drain/pipe flows, you can set the drain/pipe gradient to a fixed value, which is easier to set than individual drain/pipe start/end IL.