O2O Demand Forecasting @ISF2026, Montreal

My first International Symposium of Forecasting, a.k.a. ISF, was in Rotterdam in 2014, when I made a presentation about Global Energy Forecasting Competitions. I loved the conference and community, so I came back to ISF2015 in Riverside, CA, and the following year in Santander, Spain. Since 2014, I have attended every ISF except the one in Oxford due to COVID. I was elected as a director of International Institute of Forecasters in 2017, and re-elected in 2021. I co-chaired the ISF2025 in Beijing, right after the end of my second (and last) term. 

During past 9 years, I was involved more as an organizer than a conference attendee. My attention was mostly on how well the conference was run, how coherent the program was, and how to better serve the members of IIF. As the premier conference in forecasting, ISF only allows a speaker to make one presentation. I did not really put in too many thoughts about the one and only presentation I can give at ISF. Of course, I chose the easiest route, presenting an energy forecasting talk every time. 

This year, I realized that I now had an opportunity to enjoy ISF as an attendee. Maybe I should try something different for my conference talk. Well, I did. I picked a topic in online take-out food delivery: A three-level hierarchy for O2O demand forecasting. It's based on a paper recently accepted by the International Journal of Forecasting. 

Our IJF paper should be online soon, but I want to share some takeaways outside the paper, which might be beneficial to the forecasters from other fields.

1. It takes some courage to break the status quo.

This IJF paper was related to hierarchical forecasting of online to offline takeout food delivery demand. The original ask was just to develop the forecasts, which could have been done simply by using some off-the-shelf software packages. However, we quickly found out that the existing hierarchy was not optimal for neither business management nor hierarchical forecasting. We then took a detour to investigate the methodologies to construct the hierarchy, which eventually turned into this paper. 

2. The same idea can be applied to seemingly different applications and industries

The core idea of this IJF paper was originally from my master thesis back in 2008. It was later adopted by my wife in her doctoral dissertation in 2010. My master thesis was on electric load forecasting, while her dissertation was on supply chain. The O2O forecasting problem did not even exist at that time! Sometimes we just need to think outside the box, or explore outside the traditional boundaries of the disciplines.

3. It's important to build a comprehensive toolbox early. 

During my years as a student, I took many courses from many different departments. Some were due to degree requirements, while others were not closely related to the degrees I was pursuing. At that time, I often wondered whether those materials were going to be useful. For instance, as of today, I have never directly applied anything I learned w.r.t. assembly language. On the other hand, I have encountered a good number of problems that I could solve easily thanks to the tools I picked up in school. This paper is an example. The methodology we proposed involves clustering. To invent custom solutions to this novel problem, we need some decent understanding of optimization. Without those tools, I would have not even thought about customizing the hierarchy for hierarchical forecasting. 

4. IJF editors and reviewers are awesome!!!

This paper went through many rounds of review. I think it's four or five rounds. If counting the reproducibility check, it's even more. I really appreciate the detailed and constructive criticisms offered by the editors and reviewers. It took us a significant amount of time to revise the paper, which helped improve our work. Unfortunately I don't know who they are due to the double-blind review process. Here I want to express my sincere gratitude for them to invest the time helping us make the paper better.

My talk was very well attended with standing room only. Some folks later told me that they couldn't get into the session because the classroom was so packed. I think I made a good decision to break the status quo, by presenting a non-energy talk at ISF.

Mark your calendar for the 47th ISF, Paphos, Cyprus, June 20th to 23rd, 2027.

Lara Kretschmer: Captain

Today (April 14, 2025), Lara Kretschmer defended her master thesis Value-added Analysis of Electricity Price Forecasts via Battery-based Energy Arbitrage.

Lara received her bachelor's degree in mathematics and a graduate certificate in data science and business analytics from UNC Charlotte in May 2024. Right after that, she came to our department to pursue the master of science degree in engineering management. 

Lara Kretschmer's master thesis defense

From left to right: Dr. Tao Hong, Lara Kretschmer, Dr. Churlzu Lim. (on zoom: Dr. Lin Ma)

She set a record by finishing our MSEM program in just one year, with a thesis. 

She set this record while playing NCAA Division I volleyball!

Lara is a student athlete, born and raised in Germany. In 2020, she was recruited to UNC Charlotte on the athletics scholarship to play volleyball. In the 2024-25 season, also her 5th and last season at Charlotte, she served as a co-captain of our volleyball team. She was also named to the College Sports Communicators Academic All-District Team.

From her weekly reports, I can see many weeks of 70+ hours. Every week, she spent countless hours in the gym, for workouts, practices, and games.  Sometimes she had to travel to other states to play, adding another 10 to 20 hours on the road. On the academic side, I told all my BigDEAL students to take the most challenging courses on campus. Lara is of no exception. 

Lara is a straight-A student. 

I must be the luckiest professor in the world. I don't know what else I should dream of. 

Well, I wish she can continue pursuing her PhD, but Lara wanted to play volleyball. She plans to join a semi-pro volleyball team in Germany, while taking a day-time job in the industry.

Update 10/3/2025:

After graduation, Lara went back to Germany. She is a forecaster and demand planner at Delta Dore Rademacher, while she continues playing her favorite sports, volleyball, at a local semi-pro team. 

Lara visited me today with a hard-copy of her thesis. 

Congratulations, Dr. Li!

Today (Oct 6, 2022) Yike Li defended his doctoral dissertation on short-term ex ante load forecasting. 

Yike joined our MSEM program in Fall 2018. He completed his master thesis under my supervision in Spring 2020. After that, he continued working with me to pursue his PhD.

The COVID-19 pandemic did not slow him down at all. Instead, the lockdown days may have speeded up his research. Towards the end of his PhD journey, I was frequently surprised by the amount of work he has done within a short timeframe between our meetings. 

From January 2021 to May 2022, Yike worked at Duke Energy as a Data Scientist intern, where he built predictive models to understand consumer electricity usage. After that, he spent a summer with Cruise. While Yike received many offers during the past few months, he decided to bring his talent back to Cruise after graduation. 

While the load forecasting literature is dominated by ex post forecasting studies, many practical issues with ex ante forecasting have never been thoroughly studied. Yike's dissertation tackled some of the most difficult problems in ex ante load forecasting. I'm glad to see that he is applying these skills in the transportation sector. 

Thanks to Yike, I can tell my department chair: "My student makes more than your Dean!"

Congratulations, Dr. Yike Li!

Jordan McCorey - MVP

Last Thursday (April 15th, 2021), Jordan McCorey defended his master thesis Forecasting Most Valuable Players of the National Basketball Association.

Jordan McCorey received his B.S. in Mechanical Engineering from NC A&T University in 2017. Right after graduation, he started his full time job at Boeing in North Charleston as a process engineer. He joined our Master of Science in Engineering Management as a part-time student in Fall 2018. 

Jordan McCorey's master thesis defense
From left to right: Dr. Tao Hong, Dr. Linquan Bai, Jordan McCorey, and Dr. Pu Wang

MVP, a.k.a. Most Valuable Player, is the highest individual award for the most performing player in the entire league. If I were asked to name the MVP among all the graduate students in our program during this pandemic year, Jordan McCorey would be the one.

I have always been interested in sports, basketball in particular. After ISF2019, I sent an email to our graduate students list with a few project topics. One topic was sports analytics - NBA forecasting. Jordan responded to my email with a passionate cover letter expressing his strong interest.

We quickly set up a phone call to discuss a plan to move forward. During the phone call, I was very pleasant to know that Jordan was a varsity basketball player in high school. His understanding of the game was definitely a big plus for this topic. On the other hand, I also got to know that he has limited experience in programming, statistics, and forecasting.

I explained the challenge to him. Apparently he didn't back off. Then I asked him to take my forecasting course, which is known as one of the most demanding courses on campus. The COVID-19 pandemic hit us right in the middle of Spring 2020 semester. Many students took the easy route by taking a passing grade. Jordan, however, worked extra hard to earn a solid A while working on his full-time job at Boeing. 

Due to the quarantine, I was never able to meet Jordan in person. Instead, we had many phone calls to discuss his plan of study, research progress, and of course, our shared passion about the game of basketball. 

A few weeks before his defense date, I got a call from Jordan telling me that he just had Achilles injury. That's the same injury that led to Kobe's retirement, and the same injury that took down Kevin Durant during Game 5 of 2019 final. I asked him if he wanted to postpone the defense. He said no.

Then it came the defense date. 

A fabulous presentation Jordan delivered. 

I was super impressed, so were the other two committee members. 

Jordan McCorey, MVP of the 2020-2021 academic year. 

Deeksha Dharmapal - Well-rounded

Today (4/7/2020), Deeksha Dharmapal defended her master thesis on Gross Domestic Product for short-term load forecasting.

Deeksha received her B.S. in Civil Engineering from Bangalore Institute of Technology, India, in 2012. Prior to joining UNC Charlotte in Fall 2018, she had several years of industry experience in India, with Amazon and EMC2 (now DellEMC). During her graduate study at our program, she also completed a summer internship at Bosch Rexroth, Charlotte.

During the past few years, I gave a departmental seminar to new graduate students every year. Deeksha is definitely the one that left the best impression on me. Most students at the seminar stayed quiet, while Deeksha was one of the few asking questions. Her questions sounded genuine and intelligent. Nevertheless, I didn't think she would eventually join my group, because she appeared to have a bright future on the managerial track.

Among the students in our program, the self-motivated ones start looking for their faculty mentor rather early. Deeksha took an unique approach. She showed up at one of my MS student, Shreyashi Shukla's thesis defense. Later she signed up and completed my forecasting course, which was a surprise to me.

When she told me that she wanted to join my group, I gave her the same task, passing two SAS programmer certification exams. She completed the base one, but failed the advanced one in her first attempt. The outcome didn't surprise me, because I knew her programming background was weak at that time. Most students at this point would just give up and look for other professors. She didn't. Finally she got the SAS Advanced Programmer Certification. Since she didn't pass it within the time limit I assigned, I gave her an extra task, which she completed in time. I brought her to BigDEAL as my MS thesis student in the summer of 2019.

The thesis topic I gave her was non-trivial. Economic indicators are typically used for long term load forecasting but not short term load forecasting. I asked her to investigate what are the situations that we should consider economy, GDP to be specific, in short term load forecasting. This research involves a lot of programming skills as well as knowledge in statistics.  She picked up those things along the way, and had the thesis beautifully done.

As a forecaster, I love to investigate the things that I failed to predict. I was wondering how a little girl Deeksha surprised me multiple times by pushing herself out of her comfort zone and fighting such a tough uphill battle. Through some casual conversations, I learned that she was a student athlete. She ran track for the most part of her student life - short distance sprints and relay. She was on the basketball and volleyball teams. Post marriage, she has been playing competitive badminton.  I guess the sports experience must have built her a strong heart!

Congratulations, Deeksha!

Congratulations, Dr. Masoud Sobhani!

On March 12, 2020, Masoud Sobhani defended his doctoral dissertation on Delivery Point Load Forecasting. It was right before the coronavirus lockdown. Today, all his forms have gone through the approval chain.

Masoud joined UNC Charlotte's Master Program in Engineering Management in Spring 2016. He completed his M.S. degree in Engineering Management in December 2017 under my supervision. After that, he continued pursuing his PhD in Infrastructure and Environmental Systems.

Masoud is a great teacher. He is by far the only student in my lab being nominated for the Outstanding Graduate Teaching Assistant Award at the university level. As the graduate program director, I have to assign graduate teaching assistants to all graduate and undergraduate classes my department offers. Sometimes several colleagues ask me for Masoud to be their TA at the same time!  I had the fortune of having him help with four of my courses: forecasting, energy analytics, computational intelligence, and case studies in the energy industry. Sometimes I asked him to give lectures. During these coronavirus lockdown days, all of us professors have to move the course online. For some lectures, I can find no better resources other than recordings of Masoud's from last year!

Masoud is gifted for his leadership. During his tenure in my research group, he led two BigDEAL teams to win the NPower competitions. As a graduate student of UNC Charlotte, he is a leader of Iranian student body. As the teaching assistant, he led a team of students putting the course project into a high quality journal paper, which is the first and only class paper ever published from the courses I taught at UNC Charlotte. 

Upon graduation, Masoud published two journal articles. He also won the ISF travel grant to present his research at ISF 2018 in Boulder, CO. Masoud's research has advanced the state-of-the-art by several years. This is largely due to his two internships at NCEMC during the summers of 2018 and 2019. His research outcome has already been put in production environment by the cooperatives. Unfortunately, he experienced the dark side of today's peer review system, just like my experience 10 years ago. The core contribution of his dissertation was underappreciated by inexperienced reviewers.

Masoud passed his PhD Qualifying Exam in Fall 2018, completed his proposal defense in Spring 2019.  He was ready and going to defend his dissertation last semester, to keep up with my record of two-year PhD. Right after he came back from the summer internship, Duke Energy immediately took him before any other companies did,  which delayed the graduation a bit. Still, with a defense data in March 2020, he completed his PhD in 2.5 years, which is remarkably fast!

Now Masoud and his beautiful wife live in a luxury apartment in the city center, minutes away from Duke Energy. I wish I had that life style!

Again, congratulations, Dr. Masoud Sobhani!

Yike Li - Eager to Learn

Last Friday (2/14/2020), Yike Li defended his MS thesis, Optimal Weather Station Selection for Electric Load Forecasting.

Yike Li's MS thesis defense
From left to right: Dr. Tao Hong, Yike Li, Dr. Pu Wang and Dr. Linquan Bai

Yike received his B.S. degree in Applied Physics from Tianjin University, China, in 2010, and his M.S. degree in Electrical Engineering from North Carolina State University in 2012. He joined our MSEM program in Fall 2018. Meanwhile, he also enrolled in our INES PhD program. From 2012 to 2019, he had a progressive career in the power industry. His was promoted to a consulting manager at Accenture last year, and then decided to come back to school to pursue his PhD.

I got to know Yike since his days at NC State University. I was giving lectures on load forecasting and demand response, when he was one of the students in the class. At that time, he was definitely the student showing most interest in the subject. He was eager to learn, and asking me many questions about the software, models, and applications. Since then, we have been keeping in touch. Occasionally, he sent me greeting messages and updates about his progress in the industry. 

Couple years ago, Yike asked me about pursuing a PhD degree under my supervision. Since he didn't have thesis writing experience, I asked him to complete a master thesis first. Although I've known him for years, I still had him going through the BigDEAL interview process including the screening tests. He passed them without a surprise. His thesis topic is a continuation of my IJF paper on weather station selection. The task was to propose a method beating the one in my IJF paper. It was not an easy task, but he nailed it. He was able to complete the thesis research while working full time. 

Now he can focus on his dissertation research!

Congratulations, Yike!

Zehan Xu - Pursuing Perfection

Yesterday (April 1, 2019), Zehan Xu defended his MS thesis Customer Attrition Modeling and Forecasting.

Zehan Xu's MS thesis defense
From left to right: Dr. Linquan Bai, Zehan Xu, Dr. Tao Hong, and Dr. Shaoyu Li

Zehan received his B.S. degree in Industrial and Systems Engineering from Virginia Tech in 2016. He joined our MSEM program in Fall 2017.

During his first semester, I gave a seminary talk about the research opportunities at BigDEAL. He approached me after that, passed the tests I gave him, and officially joined my research group in February 2018.

Knowing his solid math background, I asked him to work on forecasting customer count using survival analysis. The topic was an extension of Jingrui Xie's MS thesis and TSG paper. Since Zehan did not have much background in statistics, he had to teach himself about survival analysis. He quickly figured out that the tools working well on those textbook examples are not optimal for the real-world datasets I gave him. During the past year, he has been refining his work and finally came up with an effective methodology.

Our original plan was to have him graduate at the end of 2018, when I considered the quality of his work exceed a MS thesis level. Nevertheless, he was never satisfied until very recently.

I stopped by my office last Sunday, and saw one of my student Saurabh Sangamwar in the conference room presenting something. Since Saurabh already defended his thesis a month ago, I was a little curious. I went in and found him and another BigDEAL student Yike Li working with Zehan on Zehan's defense rehearsal.

I thought Zehan's defense preparation was done, but apparently he was pursuing that perfection.

His defense was very well done. I was impressed!

While advising him for the thesis research, I found Zehan a great candidate for doctoral research.  He also realized the need and value of advanced education, so he decided to continue pursuing his doctoral degree here at BigDEAL.

Congratulations, Zehan!

Saurabh Sangamwar - Nothing is Impossible

Yesterday (February 12, 2019),  Saurabh Sangamwar defended his MS thesis Grouping Calendar Variables for Electric Load Forecasting.

Saurabh Sangamwar's MS thesis defense
From left to right: Dr. Liquan Bai, Saurabh Sangamwar, Dr. Pu Wang, Dr. Tao Hong

Saurabh received his B.Eng. in Mechanical Engineering from K J Somaiya College of Engineering, Mumbai, in 2015. After working in India for two years, he joined our MSEM program in Fall 2017. 

I still remember the scene of our first conversation a year ago, when he expressed his interest in joining BigDEAL.

"learn SAS and get the SAS Base Programmer Certification." I told him the same as what I said to the other students.

"I did." Saurabh said. 

"Then go ahead and get the SAS Advance Programmer Certification." I responded. 

"I've done that too." He said. 

Apparently, he came to me so well prepared, and he was the first student I met this well prepared. 

I admitted him without a blink. 

The topic I gave him is about grouping calendar variables. It took him a while to get the preliminary results. Then I asked him to change a few parameters in his algorithms, and refresh the results. I took him another long while to get the second batch done. I saw him working hard everyday, so I was wondering why it took so long to get the results. During the conversation, I realized that his code is not fully automated. In other words, he had to do a lot of manual work to get the results. I also understood that he did have any programming background until last semester, when he was preparing for the SAS certification exams. 

I'm a professor who likes to pull the students out of their comfort zone. Knowing his weakness, I increased the programming requirements in his master thesis research, so that he can sharpen his programming skills. 

Saurabh did not disappoint me. Over the following few months, he automated his code, picked up parallel computing techniques, and even learned additional languages such as Python and R. Moreover, he is one of the few students took two tough courses from me and got a 4.0 GPA. 

To Saurabh, nothing is impossible. 

Congratulations!

Shreyashi Shukla - Determined to Excel

Today (October 23, 2018), Shreyashi Shukla defended her MS thesis Daily Load Forecasting Using Hourly Temperatures.

Shreyashi Shukla's MS thesis defense
From left to right: Dr. Tao Hong, Shreyashi Shukla, Dr. Simon Hsiang, Dr. Churlzu Lim

Shreyashi received her B.Tech. with Honors in Production Engineering & Management from National Institute of Technology, Jamshedpur, in 2006. Before moving to the U.S. with her family, she had a 10-year progressive career in the energy sector in India. She joined our MSEM program in Fall 2017.

Every year I give a department seminar to share with the students about the research projects at BigDEAL. The purpose of these seminars is two-fold. On one hand, these seminars can broaden the students' view about systems engineering and engineering management. On the other hand, I would like to attract the most self-motivated and talented students from the program.

While most students were scared away after seeing how productive the BigDEAL students are, Shreyashi was one of the fearless students who contacted me after the seminar. During our first conversation in October 2017, I explained to her my expectation, and told her about the BigDEAL entrance tests. She took the challenge, passed the tests, and officially joined BigDEAL in Janurary 2018 to conduct her MS thesis research under my supervision.

The research problems BigDEAL students work on are never easy. In addition to tackling the research challenge, Shreyashi had the family duties too. Everyday she spends the morning on campus working on her coursework and research, and the rest of the day with her little daughter at home. She always comes to the lab on time, leaves on time, and works very efficiently. 9 months later, her research turned into a solid MS thesis, which made her the third "mom" student completing MS thesis research at BigDEAL (after Jingrui Xie and Ying Chen). She is also my first Indian student. Next semester, Shreyashi will continue working with me towards her PhD degree.

Congratulations, Shreyashi!

Masoud Sobhani - From Petroleum Engineer to Load Forecaster

Today (November 27, 2017), Masoud Sobhani just defended his MS thesis on data cleansing, the first BigDEAL thesis authored by a non-Chinese student.

Masoud was a petroleum engineer in Iran. He migrated to the U.S. several years ago. He first came to my office in 2015 with inquiries about our MS Engineering Management program, when I was the program director. At that time he could barely speak English. Nevertheless, I admitted him to the program mainly because of his solid academic background and industry experience in the energy sector.

He started the program in Spring 2016 to pursue a non-thesis master degree, planning to graduate in Summer 2017. Due to the challenging nature of my courses (see some student comments HERE), most of the non-thesis master students in our MSEM program try their best to avoid them. Masoud is certainly an exception. He managed to take all my courses during his tenure in the program. At Npower forecasting challenge 2016, Masoud took a top 3 place.

In Spring 2017, he came to me to discuss the possibilities of pursuing a PhD under my supervision. Recognizing him as the top student in the program, I agreed to take him as my doctoral student with the condition that he completes a MS thesis by the end of the year. He took the challenge. From May to November, he passed SAS Advanced Programmer certification exam, identified his thesis topic, designed and implemented a novel data cleansing algorithm, and finished his 10,000-word thesis. The defense was very well done.

Congratulations, Masoud, and best luck with your PhD journey!

Congratulations, Dr. Jingrui Xie!

Today (October 13, 2016), Jingrui (Rain) Xie defended her doctoral dissertation on probabilistic electric load forecasting, which made her the first BigDEAL PhD.

When coming back to academia three years ago, I had the mission of producing the next generation of finest analysts for the industry. As the first PhD from BigDEAL, Rain sets the standard for BigDEAL products and tells what the finest analyst looks like.

Rain joined UNC Charlotte in August, 2013, as my first master student. She received her M.S. degree in Engineering Management in May, 2015, and continued with her PhD in Infrastructure and Environmental Systems.

In just three years, she published 7 journal papers:

• Temperature scenario generation for probabilistic load forecasting (TSG, in press)
• Relative humidity for load forecasting models (TSG, in press)
• On normality assumption in residual simulation for probabilistic load forecasting (TSG, 2016)
• GEFCom2014 probabilistic electric load forecasting: an integrated solution with forecast combination and residual simulation (IJF, 2016)
• Improving gas load forecasts with big data (GAS, 2016)
• Long term retail energy forecasting with consideration of residential customer attrition (TSG, 2015)
• Long term probabilistic load forecasting and normalization with hourly information (TSG, 2014)

and 3 conference papers:

• Comparing two model selection frameworks for probabilistic load forecasting (PMAPS, 2016)
• From high-resolution data to high-resolution probabilistic load forecasts (T&D, 2016)
• Combining load forecasts from independent experts: experience at NPower forecasting challenge 2015 (NAPS, 2015)

She was among the top contestants in all of the forecasting competitions she participated:

• Top1 in BigDEAL Forecasting Competition 2016
• Top 3 in NPower Gas Demand Forecasting Challenge 2015
• Top 3 in NPower Electricity Demand Forecasting Challenge 2015
• Top 3 in Load Forecasting Track of Global Energy Forecasting Competition 2014

She has also received several prestigious awards:

• 2016 IEEE PES Technical Committee Prize Paper Award
• International Symposium on Forecasting 2016 Travel Award
• 2015 IEEE Transactions on Smart Grid Best Reviewer Award
• 2015 Foundation of the Association of Energy Engineers Scholarship
• International Symposium on Forecasting 2015 Travel Award
• 2015 UNCC College of Engineering Outstanding Graduate Research Assistant Award
• 2015 International Institute of Forecasters Student Forecasting Award

Rain has been full-time working at SAS during the past three years. In addition to the academic excellence, Rain received a promotion earlier this year for her outstanding performance at work. 

It took her 21 months to get the PhD - she enrolled in the PhD program in January, 2015, and defended the dissertation today. That said, she just proved the reproducibility of my 20-month PhD!

Lastly, but most importantly, she became a mother two years ago - her daughter is now two-year old. 

Again, congratulations, Dr. Jingrui Xie!

My Path to Forecasting

The International Institute of Forecasters posted my profile this week.

How did you become a forecaster?

My path to forecasting was more like a maze than a straight line.

In 2005, I joined North Carolina State University’s Electrical Engineering doctoral program. Halfway through my PhD study, in January 2008, I started working in a consulting firm as an electrical engineer, providing services to the energy and utility industries. My first project was on long term spatial load forecasting – forecasting the 30-year ahead annual peak demand for each 50-acre small area of a US utility. In today’s terminology, it is a hierarchical forecasting problem. Knowing almost nothing about forecasting at that time, I formulated the problem as an optimization problem: minimizing the errors in the historical fit and the discrepancies between the sum of lower level forecasts and the upper level forecast, subject to some constraints on saturation load level and load growth rate, etc. I wrote thousands of lines of code in VBA to solve it. I also developed a user interface in MS Excel for power system planners to override the parameters estimated by the computer and see the results on a map. Finally, the solution was very well received by the customer and then sold to many other customers. I also packaged the work into a thesis when I got my master’s degree in operations research and industrial engineering.

At the end of 2008, I was tasked with forecasting hourly electricity demand for another US utility. It was a competition – if my forecast won, the customer would give us a big contract. While the spatial load forecasting project did not require a rigorous evaluation based on the forecast accuracy, this one did. I knew I couldn’t win without getting some statistical forecasting skills. With the help from my wife, a forecaster working at SAS, we developed a linear model that eventually led to a big consulting contract to develop a short term load forecasting solution. In 2009, I joined the Operations Research PhD program of NC State while developing and delivering that short term load forecasting solution at work. I took some time series forecasting courses from David Dickey, who later joined my doctoral committee. In 2010, I completed the dissertation “Short Term Electric Load Forecasting” and received my PhD in operations research and electrical engineering. That’s when I first considered myself a forecaster.

What did you do after getting your PhD?

I continued working in that consulting firm for another few months. In 2011, I got an offer from SAS to work on some forecasting projects for large retailers. The problem was very challenging and interesting to me – how to forecast millions of products on weekly basis? At that time, smart meters were just being deployed in the US. The data would not be ready for analysis for a year or two. I thought it would be nice to take some time off from the utility industry and learn from other industries that had been dealing with hierarchical time series data for decades. I took the offer and became an analytical consultant at SAS for their retail business unit. In January 2012, the General Manager of SAS’ newly formed utilities business unit recruited me to build the energy forecasting vertical. Then I lead a team to commercialize my doctoral research into the SAS Energy Forecasting solution. After the solution was successfully launched, I headed to the next challenge – the workforce crisis in the energy industry. In August 2013, I came back to academia to become a professor, with the mission of educating the next generation of analysts.

What areas of forecasting interest you?

I’m most interested in energy forecasting, more specifically electricity demand forecasting, an area I’ve been working on since the beginning of my forecasting career. Electricity demand typically comes in with high resolution, long history, strong correlation with weather, and sometimes a hierarchy. We can use the load forecasting problem to demonstrate many forecasting techniques and methodologies. Moreover, the problem is so important because it’s tied to the life quality of billions of people on this planet. In addition to energy forecasting, I also have experience and strong interest in retail forecasting and sports forecasting. Recently, I started working on forecasting problems in the healthcare industry, another fascinating field.

Are you working with companies to improve their forecasting practices?

Yes. I maintain active consulting practices through Hong Analytics. Every year I teach 5 to 10 training courses internationally, and work on a few consulting projects to tackle some problems that are challenging in nature. These consulting projects and interactions with clients have inspired many novel research ideas. We turn these ideas into scholarly papers and teaching materials. Many other companies use our papers to improve their forecasts and forecasting practices.

What’s your proudest accomplishment in forecasting?

I have several accomplishments to be proud of, such as commercializing both my master thesis and doctoral dissertation research into software solutions, founding the IEEE Working Group on Energy Forecasting, and authoring a blog on energy forecasting, Nevertheless, my favorite one is the Global Energy Forecasting Competition. It was a team effort. Thanks to a group of enthusiastic scholars and the sponsorships from IEEE Power and Energy Society and the IIF, we have organized two competitions so far: GEFCom2012 and GEFCom2014. Both competitions attracted hundreds of participants worldwide. In addition to highlighting the winning methodologies, these competitions have made data publicly available, to encourage and enable reproducible research in the energy forecasting community. We are currently planning for the next competition. Stay tuned :)

What do you do in your free time?

Other than the family time and work time, I love blogging the most. I started my blog Energy Forecasting in 2013 after seeing Rob Hyndman’s blog Hyndsight. In 2015, the blog attracted 12,119 users from 2,146 cities across 134 countries. In my normal life as a professor living in the peer review system, I had to constantly fight with anonymous reviewers. Blogging is also an escape for me – nobody can reject my post other than myself!

BigDEAL Students Receiving Promotions

As a professor, I find nothing better than hearing the success stories of my students. Currently I have two PhD students, Jingrui (Rain) Xie and Jon Black. Both of them are also working full time in the industry. This is the season of promotion announcements in many companies. Rain was promoted from Sr. Associate Research Statistician Developer to Research Statistician Developer, while Jon was promoted from Lead Engineer to Manager. Here I'm very pleased to feature their short biographies with the new business titles. For more details about their profiles, please check out the BigDEAL current students page.

Congratulations, Rain and Jon, for the well-deserved promotions!

Jingrui Xie

Jingrui (Rain) Xie, Research Statistician Developer, Forecasting R&D, SAS Institute Inc.

Jingrui (Rain) is pursuing her Ph.D. degree at UNC Charlotte where her research focuses on probabilistic load forecasting. Meanwhile, she also works full-time as a Research Statistician Developer at SAS Forecasting R&D. At SAS, she works on the development of SAS forecasting components and solutions, and leads the energy forecasting research. Prior to joining SAS Forecasting R&D, Rain was an analytical consultant at SAS with expertise in statistical analysis and forecasting especially on energy forecasting. She was the lead statistician developer for SAS Energy Forecasting solution and delivered consulting services to several utilities on load forecasting for their system operations, planning and energy trading.
Rain has extensive experience in energy forecasting including exploratory data analysis, selection of weather stations, outlier detection and data cleansing, hierarchical load forecasting, model evaluation and selection, forecast combination, weather normalization and probabilistic load forecasting. She also has extensive knowledge and working experience with a broad set of SAS products.

Jonathan D. Black

Jonathan D. Black, Manager of Load Forecasting, System Planning, ISO New England Inc.

Jon is currently Manager of Load Forecasting at ISO New England, where he provides technical direction for energy analytics and both short-term and long-term forecasting of load, distributed photovoltaic (PV) resources, and energy efficiency. For the past three years he has led ISO-NE’s long-term PV forecasting for the six New England states based on a variety of state policy support mechanisms, and provided technical guidance for the modeling of PV in system planning studies. Jon is directing ISO-NE’s efforts to develop enhanced short-term load forecast tools that incorporate the effects of behind-the-meter distributed PV, and has developed methods of estimating distributed PV fleet production profiles using limited historical data, as well as simulating high penetration PV scenarios to identify future net load characteristics. Jon participates in industry-leading research on forecasting and integrating large-scale renewable energy resources, and has served as a Technical Review Committee member on several multi-year Department of Energy studies. Upon joining ISO-NE in 2010, Jon assisted with the New England Wind Integration Study and the design of wind plant data requirements for centralized wind power forecasting.
Mr. Black is currently a PhD student researching advanced forecasting techniques within the Infrastructure and Environmental Systems program at the University of North Carolina at Charlotte. He received his MS degree in Mechanical Engineering from the University of Massachusetts at Amherst, where his research at the UMass Wind Energy Center explored the effects of varying weather on regional electricity demand and renewable resource availability. He is an active member of both the Institute of Electrical and Electronics Engineers (IEEE) and the Utility Variable Generation Integration Group (UVIG).

BigDEAL Students Winning NPower Gas Demand Forecasting Challenge 2015

RWE npower hosted its second forecasting challenge in 2015 last month. The topic was ex post 6-month ahead daily gas demand forecasting with hourly weather information.

44 teams worldwide joined the competition, of which 22 were from U.K. Three of my students (Jingrui Xie, Bidong Liu and Ying Chen) formed the team BigDEAL@UNCC to join the competition. 

Ying Chen - From Meteorology to Energy Forecasting

Today (October 21, 2015), Ying Chen just defended her MS thesis "How Does Relative Humidity Affect Electricity Demand?"

Ying received her B.S. in Atmospheric Science from Nanjing University of Information Science and Technology in 2006, and her M.S. in Meteorology from University of Hawaii at Manoa in 2010. In August 2014, Ying joined the Master of Science in Engineering Management program of UNC Charlotte as a member of BigDEAL to conduct MS thesis research under my supervision.  She received her SAS Base Programmer and SAS Advanced Programmer certifications in fall 2014. She participated in the Global Energy Forecasting Competition 2014 with a top 9 place in the probabilistic solar power forecasting track. This past summer, Ying presented her research work at the 3rd International Conference on Energy & Meteorology.

Since October 2014, Ying has been working at North Carolina Electric Membership Corporation as a Load Forecasting Analyst Intern. This December, She will receive her MS in Engineering Management.

Congratulations, Ying!

BigDEAL Students Receiving Awards from Lee College of Engineering

Today (April 21, 2015), William States Lee College of Engineering hosted an award luncheon to celebrate student achievements. I'm very pleased to see two of our BigDEAL students being recognized in this event:

• Jingrui (Rain) Xie received the Outstanding Graduate Research Assistant Award. I recently highlighted Rain's achievement in THIS POST. 
• Bidong Liu received the Outstanding Graduate Student Award, mainly for his leadership to win the poster contest of Analytics2014 and NPower Forecasting Challenge 2015. 

Moreover, we had the first full house today with all BigDEAL members gathered on campus. Here is a selfie we took after the award luncheon. Thanks to Bidong's selfie stick :)

BigDEAL Selfie - Spring 2015

Congratulations, Rain and Bidong!

Jiali Liu - The First Alumna of BigDEAL

Today (April 16, 2015), Jiali Liu just defended her MS thesis on combining sister load forecasts, which made her the second graduate of BigDEAL. Since the first BigDEAL graduate Rain is continuing her PhD study here, Jiali becomes the first alumna of BigDEAL.

Jiali received her bachelor degree in International Business and Trade from Wuhan University of Technology, and her second bachelor degree in Business Administration from University of Pittsburgh, both in 2012. In August 2013, Jiali joined the Master of Science in Engineering Management program of UNC Charlotte. In May 2014. She joined BigDEAL to conduct MS thesis research under my supervision. She received her SAS Base Programmer and SAS Advanced Programmer certifications in summer 2014. She was part of the BigDEAL team winning the Analytics2014 poster contest. She was also a key contributor to the EISPC/NARUC Load Forecasting Case Study. She participated in the Global Energy Forecasting Competition 2014 with a top 8 place in the probabilistic wind power forecasting track.

Jiali received her Graduate Certificate in Energy Analytics in December 2014. This May, she will receive her MS in Engineering Management degree with a concentration in Energy Systems. After that, Jiali will join Carolina Healthcare Systems as a Statistician.

Congratulations, Jiali, and all the best!

Jingrui Xie - The First Graduate of BigDEAL

Today (April 2, 2015), Jingrui (Rain) Xie just defended her MS thesis on retail energy forecasting, which made her the first graduate of BigDEAL.

Rain received her B.A. in Finance from Sun Yat-sen University in 2009, and her M.A. in Economics from Duke University in 2011. In August 2013, Rain joined the Master of Science in Engineering Management program of UNC Charlotte as my first student. Since then she has published two journal papers, one on long term probabilistic load forecasting, and the other on retail energy forecasting. She was a key contributor to the EISPC/NARUC Load Forecasting Case Study. She was part of the BigDEAL team that topped the NPower Forecasting Challenge 2015.  As one of the top teams of the Global Energy Forecasting Competition 2014, she was invited by International Journal of Forecasting to write a paper describing her winning methodology. This summer, Rain will be attending two conferences, International Symposium on Forecasting and IEEE Power and Energy Society General Meeting, to present her work on probabilistic load forecasting.

Rain will continue her study in the Ph.D. Program in Infrastructure and Environmental Systems (INES) here at UNC Charlotte. Her dissertation topic is on probabilistic load forecasting.

Congratulations, Rain!

BigDEAL Students Topping NPower Electricity Demand Forecasting Challenge 2015 with The Most Robust and Accurate Forecasts

A month ago, I posted NPower Forecasting Challenge 2015. Then four of my students (Bidong Liu, Xiaoqian Lyu, Jingrui Xie, Lili Zhang) formed a team to have fun in the competition. The competition attracted many teams worldwide. 33 teams completed the compeition, of which 23 are from U.K. universities.

This morning, the final leaderboard was just released. I was again very pleased to see the outstanding performance of the BigDEAL team:

• Ranking #3 on the average MAPE of the three rounds. The MAPE values of the three teams in the top cluster were extremely close: 2.42%, 2.47% and 2.48%. BTW, all top three teams were GEFCom2014 contestants, but not from U.K. universities. 
• The only team managing to have less than 3% MAPE in all three rounds. The highest MAPE of BigDEAL's three rounds was 2.84%, which was the lowest one among all 33 teams. 
• The only team ranking top 2 twice; and one of the only three teams ranking top 10 in all three rounds. BigDEAL's rankings in the three rounds were #2, #7 and #2, respectively. 
• One of the only two teams with consistently improved MAPE throughout the three rounds. BigDEAL's MAPEs were 2.84%, 2.39% and 2.21%, respectively. 

Many thanks to NPower for organizing this fantastic competition. And congratulations, BigDEAL students!